Critical Power: Renewable energy systems

thank you for joining us today for the Consulting specifying engineer webcast

0:06critical power renewable energy systems I’m your host and moderator Amara rascus

0:13with Consulting specifying engineer and CFE media and technology and I’ll be

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1:58read the quality assurance slide all right so here are the learning

2:05objectives we’ll talk about these in today’s presentation please note that any blue underlying text that you see is

2:12a hyperlink within the PDF where you can get more information

2:19all right well we’ve lined up two great presenters they’re very informed on this

2:24topic Benjamin Skelton is president and CEO of cyclone Energy Group his 20 years of

2:31experience in designs for high performance buildings from concept through operation gives him insights and

2:38vision for each project he specializes in energy efficient and sustainable buildings and is recognized as an expert

2:45in building energy simulation building commissioning and retro commissioning

2:51Sean Avery is principal and electrical engineer at DLR group his experience

2:57spans power controls and lighting design he’s involved in the design of energy

3:02efficient systems to ensure user Comfort well-being and effectiveness

3:09he’s an expert in early modeling and Analysis to inform the development of effective passive design strategies both

3:16Benny and Sean are Consulting specifying engineer 40 under 40 Award winners and

3:22I’m excited to be working with two professionals on The Cutting Edge of renewable energy

3:28so I’m eager to get this discussion started but first we want to ask for some audience input so we know what

3:36direction to take so here’s the first poll the question is what is the number one

3:42Renewable Energy System you’re asked to design or specify and I’ll give you a

3:49second or two here to respond

3:54so as these results come in we have a whole host of different options and we’d like you to pick the number one option

4:02of what you’re being asked to specify and so far the clear winner is solar

4:08voltaic but I’ll give you a few seconds here to chime in with any other options in second place we have batteries

4:16and it looks like in third place we have solar thermal so by far solar voltaic

4:24takes first place so Benny you’re up first let’s begin

4:30with this presentation now great thank you Amara

4:35great to be here today and I think everybody’s in great luck because the top three are things we’re certainly

4:41going to cover today but uh wanted to first start off by really defining all energy resources that exist out there

4:47that are both renewable or non-renewable so there are non-renewable sources that

4:53we’re familiar with these include coal crude oil natural gas uranium or plutonium used in nuclear energy

5:00these are uh you know the the using resources from the earth and and

5:05definitely not considered renewable at all now there are even more renewable

5:11resources that we can choose from we have hydropower solar wind geothermal

5:17biomass these are things that can be made from wood wood waste Solid Waste uh

5:22landfilling methane uh these are often found in farms and places like that

5:27there’s tidal power ocean thermal is an option and then crops are used you might

5:33see this through ethanol corn is a a renewable energy resources to find here

5:42so when we look back at how energy has been used in the United States at least

5:47throughout the past uh 70 years you can see that by far the most prominent source of energy

5:54production in the United States has been cold and we’ve seen a very very sharp decline

6:00of that since the year 2000 I mean we’ve seen conversely a very sharp increase in

6:05natural gas consumptions since then moving up to present day as of 2020

6:11being almost 40 percent of the total energy produced Renewables are sticking up there as well

6:17you see that starting in 2010 that climb has started to shift and they’re moving up and that’s going to continue to grow

6:24while coal continues to drop off as projections look these uh these

6:30Graphics are from the Energy Information Administration so it’s an open source website where you can get almost uh up

6:36to the date daily information on the energy markets throughout the United States so you know

6:42looking at the the total percentage as we project out to 2030 2050 a lot of

6:48cities jurisdiction States a lot of different organizations have goals set

6:54around the years 2030 in the Years 2050 for carbon reduction and Renewables are

7:00going to play a big role in that especially in the building energy consumption world so we see that 44

7:06of the power generation needed in the United States in the year 2050 is going to come from renewable energy while

7:13natural gas will be about the same you can see it grows because the the amount of energy production will need to grow

7:19and you know the predicting nuclear to stay relatively similar to where it is or less than it is now in cold to fall

7:25off to continue to fall off the map so as we look at where sources of

7:31renewable energy are going to make up that mix an overwhelming percentage of that is going to become from solar

7:38currently it’s not that uh solar is not the the highest producer right now wind

7:44is you might see a lot of large wind generation Farms if you’re going to coastal areas you’re starting to see

7:50offshore wind production and that’s all in the works to get increased between

7:56now and in 2050 there are significant efforts through Government funding through administrative planning to try

8:03to get more large-scale production but as we look at it on a building level what can we do solar is going to be that

8:09place that’s going to pick up now we spent a lot of news uh about grids infrastructure and resilience and

8:18you know grids and infrastructure resilience these all kind of tailor towards things around potentially climate change or the need that we need

8:25to have a more secure infrastructure in the United States to secure our power uh there’s talk about how renewable energy

8:31can make our grids unstable and so uh finding ways to make the grid stable and

8:38balance the renewable energy is a very important part of the equation going forward but we saw just last year the

8:46Texas power grid failed during a winter storm unseasonable winter storm took the entire State down and cost you know

8:52billions of trillions of dollars worth of damage to buildings and infrastructure there recently there’s

8:59been talk about Lake Powell a very large hydroelectric producer uh actually

9:04reaching a critical low point to where it wouldn’t be able to produce hydroelectric power impacting something

9:10like 5.3 million users there’s already been some hydroelectric in the west

9:15that’s been shut down because of the the drought and the low water levels on a conversely interesting note the

9:22state of California was briefly uh fully powered by renewable energy last month there was a brief moment where they

9:28produced more energy than it uh actually consumed and but at the same time they

9:34did this through Renewables they still had to have sources of power such as natural gas online to provide

9:42that bulk power but things are changing the the there are certain to see the infrastructure

9:48and they’re starting to see the production increase there uh and one thing that’s come up I think

9:53the question of weren’t you being asked to design comes around solar photovoltaics uh just recently there’s

9:59been a lawsuit and some investigation around solar providers mainly out of

10:04Southeast Asia to see if the market is fair with U.S markets and that’s caused the production or the use and

10:12installation of solar panels to slow in the United States so there’s a lot of factors that come into play when we look at these uh Renewables but I think we’re

10:19just at the at The Cutting Edge of this that things are going to get to a place where production is more linear and you

10:25can see from the predictions the estimates are looking that way as well

10:31when we look at buildings what really makes sense and it brought all the

10:37renewable sources back to the page here and kind of poorly highlighted uh the

10:42ones that do make sense but hydropower this is a utility scale Source ofable energy it’s it’s not really practical to

10:49provide hydroelectric generation on on a building site it takes a great level of

10:55water pressure to be able to turn the turbine and generate electricity so we see that at a big utility scale

11:02now solar and wind are the two applications that are site-specific and building

11:07specific that make the most sense they can be put on a building they can put next to a building they can be put on

11:12the site when we look at geothermal this can sometimes get confused in the building

11:18world as being the geothermal systems that are used for heating and cooling this is not the same that’s actually

11:26referred to as Geo exchange and that’s using the Earth as a a temperature source to both store and reject heat

11:34energy to well that seems renewable it’s not a source of energy generation it’s purely a way to store and reject energy

11:41so we we call geothermals more of actual energy outside of the earth coming up

11:46and generating that power so we see this in very volcanic areas where there’s a lot of energy in the Earth

11:53a biomass I mentioned this can be used on the building scale but it tends to apply more towards campuses when I’ve

11:59seen this done it’s in healthcare campuses or large building campuses where they have Central utility and this

12:05might be a place where they can fuel switch or Source fuels from different places but biomass is certainly

12:12something that has come up since the early 2000s and while it does have some emission factors to it there are ways to

12:18work around that and to minimize the the impact of that tidal power against a utility scale

12:25source of uh of energy this is going to be something off of major Coast to be able to generate that energy

12:31and uh ocean thermal officiency is also a utility scale thing we don’t see as

12:36many of these they’re very expensive to build there’s often a lot of restrictions about environmental

12:43restrictions around these types of sites so we we see that really in the utility world

12:48and again crops using things like corn for alcohol production as a bullet for

12:55these can be used in a campus scale uh usually it takes very specialized equipment you can get it for household

13:00scale too but it’s not one of the more common applications of Renewable Power and a lot of times when we see these the

13:07household scale it’s it’s uh not necessarily having the clean emissions

13:12factor that we might have at a at a larger scale application

13:18so focusing in on wind energy on a building site this can be complicated to get a wind energy to work you need to

13:25have a cut in speed so often that’s around five miles per hour of a constant wind speed before you start generating

13:32any energy um the the mechanisms in it to put them on a site they tend to be smaller they

13:38don’t generate a ton of energy but they they can be used but a lot of times you need to have that constant source of

13:44wind uh wind falls off a lot of times at night isn’t a great source of production there but it is something that can be

13:50used on site you do run into some things like local ordinance restrictions where

13:56you might not be able to put it on site there’s concerns about putting large wind turbines like utilities used on

14:02sites because if it fell in a windstorm does it fall on your property line we’ve seen issues around that so wind has its

14:09challenges at the small scale it’s a it’s a low producer uh at the larger

14:14scale like you see with the utilities it’s a great production source

14:20that leads me into the other good application for buildings which is solar energy solar panels can be put anywhere

14:26it’s just how much energy are they going to generate and I think uh there used to

14:31be a time when we looked at solar panels and said well we can only do it in the Southeast or the Southwest or the South where there’s higher incidence of sun

14:39exposure less cloud cover but those times have changed solar panels are much

14:44much more efficient than they were even a decade ago they could produce a tremendous amount of power and uh on a single cell and they have

14:51the ability to produce with light cloud cover and things where they might not have produced in in the past so

14:58necessarily the map isn’t restrictive anymore and and it can be beneficially applied to buildings almost anywhere

15:07and you know solar energy production is great on buildings you can apply it to a

15:12roof you can keep it on carports you can put it in places that the the you know

15:19you might see as a marketing tool for an office but you put it on your home so the solar panels can be installed our

15:24next presenter is going to go into a lot more details on on that installation but

15:30it’s very good for building infrastructure it can tie right into

15:35your Building Systems as well real briefly there are several types of

15:41solar photos out there the most common the highest efficiency rating are

15:46monocrystalline type these are what are manufactured most commonly they’re pretty readily available they have great

15:53durability can last 25 years typically under warranty for 25 years they tend to be one of the higher cost uh

16:00installations but they are the most common on the market when we see the polycrystalline these

16:07are interesting they have a different color to them typically they’re made of

16:12of crystalline that’s a mixture so it’s slightly less less efficient than the

16:19monocrystalline and they tend to be kind of the medium costs they have a pretty

16:25good durability to them as well because of the different uses of the different crystallines that are made up in the

16:30components and the last is thin cell these are the least efficient of them they’re made from several different

16:37types of things they can be made from amorphous silicone for example the benefit of this is they can kind of

16:44be made into patterns and they can be used to look anywhere that you want so you see a lot of thin film applied to

16:50Windows surfaces on the sides of building so you might see them put a custom glass they tend to

16:58be a little bit more for show but our recent experience with them is they they can have great performance value to them uh as well as a good marketing value

17:05they are the highest aggregating uh photovoltaic film that’s out there they don’t have nearly the life and they

17:12aren’t warranty for the 25 years it depends on the material that you use but you might be looking at 10 12 15 years

17:18in some of these products

17:24and uh as far as the the production of it uh you know like I said

17:31there’s different looks of it you can do a different type of

17:37wind and solar so solar you don’t necessarily have to have it at ideal angle it can be flat mounted it just

17:42won’t produce as much energy as it were if it were put at an optimal angle towards the sun there are solar panels

17:48that can track the sun they would add costs but on a large scale that might be

17:53beneficial on a building scale that’s not always these and then there are some ordinance restrictions that come with

17:58how you install solar panels on your roof that you have to be aware of fire department access sometimes you can’t

18:05put a full roof array in you need walk aisles for the fire department to not get electrocuted on the roof during an

18:11incident so there are a lot of different things that need to be taken into account are the neighboring structures that are shading the building are there

18:18trees when you look at all of these there’s a lot of limitations that can take into account but in general the

18:25solar Market has gotten to a place where it’s very applicable in the building environment

18:32and I think you know we’ve used them a lot to get towards uh Zero Energy so I think I’ll hand it over to Sean to talk

18:38a little bit more about that thanks Benny hey so start off my portion

18:43of the presentation here I I figure it’s good to level setting a couple definitions first of some phrases I may

18:50drop um throughout the presentation because there’s seems to be lots of Nets and lots of zeros that we talk about when

18:56we’re discussing these things here so um Net Zero can be defined in a handful of ways today I’m going to use it as Net

19:03Zero electrical energy um we’ll be talking about carbon or anything like that just Net Zero

19:09electrical EG net metering is the term used for being able to spin the meter in both directions that’s going to be an

19:15agreement with the utility for your that point of interconnection the solar system a net producer would mean that

19:22you are producing more than energy then your building would consume if you’re

19:27attached there this is generally not accepted under the guidance of net metering

19:33um you know there’s been talk over the years of oh well they’ll they’ll pay me for the excess energy I produce

19:39um yes and no they’ll generally allow you to produce up to amount you use in a

19:45year but they’re not usually going to write you checks for excess you do it may vary but generally that’s the case

19:50is that you want to not really exceed your consumption in a net metering scenario

19:56um zero feed in is a situation where you won’t be allowed to net meter and you

20:01need to store and use all that energy on site uh we don’t see a ton of that right now in the US but we’re starting to see

20:07it in places like Hawaii where they’re starting to get to the point of Maximum solar penetration

20:13um on their grid um so anyway I will use those terms a little bit throughout the presentation

20:18here um a couple more uh grid interactive these are going to be inverters that are

20:25grid following and um will just kind of go along with what

20:31they see the utility grid doing an off-grid you need something that’s great forming so they are going to create that

20:3760 hertz signal um and uh so that’s you need that piece

20:43in any off-grid scenario um or like Benny mentioned earlier in

20:48California still needed some conventional generation to be the grid forming piece there since so much of the

20:55solar is mostly just grid following then microgrid or hybrid systems are systems that can switch between the two

21:01grid interactive and off-grid the basic pieces of any uh solar system

21:09are shown here we’ll start with our PV modules we’re all probably familiar with those we’ll on any commercial building

21:16we’ll probably have hundreds to thousands of those on our rooftop array or carports whatever

21:22um to the right of that is a rapid shutdown device or maybe an Optimizer for rooftop solar rays we need to comply

21:30with some rapid shutdown codes and so we’ll generally have uh one of these for

21:35every one to two modules on the rooftop and they use a communication protocol in

21:40the inverter to shut contain the electricity within the module or within that device basically

21:47and the system gets shut down for fireman protection to the right of that we have some

21:53examples of some solar inverters these are converting the DC electricity to AC electricity that’s needed for the

22:00building to use most predominantly I see string inverters which is example on the top and I’ll show you sort of a wiring

22:06diagram that’s in a minute but they’re generally um in the scale of 25 to 100 kilowatts

22:14in size and then below that is a micro inverter example which

22:21would be used for again every one to two modules would have its own little inverter there and there’s pros and cons

22:28to each one and then finally once you go there you usually end up with the utility disconnect before you tie into

22:35the grid um the requirements of that vary a little bit by jurisdiction most often if

22:41they are required the utility wants you to have a viewing window on it is shown on this picture here so they can visibly

22:47see that the system is disconnected if they had to go in there and do any maintenance

22:53uh here’s an example of a one-line diagram for a string inverter I’m not going to spend a whole lot of time here

22:59but I want to make out a few points on here so we have our solar modules which

23:06produce a DC voltage of you know 50 volts plus or minus you know

23:1310 volts there just depending on the configuration and generally what we’ll do is we’ll string them in series kind

23:18of like Christmas lights up to a point where on the DC side we’re achieving volts voltage around a thousand volts so

23:24in this version here it’s probably a little hard to read but I have 18 modules in a string then I’ll start

23:31paralleling those into the inverter so in this example here again I have 10

23:36strings connected to this inverter all in parallel they’re broken into three groups which connect to a what’s called

23:43a multiple PowerPoint tracking Zone um for the sake of this conversation keeping it simple those are basically

23:50optimizing the power of the strings that are coming in um from the solar there so there the

23:57energy produced by the PB modules is they’re kind of a dumb device and they need to kind of be optimized to maximize

24:04the amount of power being pulled out of them so the different mppt zones here will

24:10allow for different orientations um this one here is three zones in it so

24:15that might be allow for three different orientations in the modules or allow for shade tolerance the micro inverters I

24:22showed earlier would do that optimization at the module level

24:33all right so let’s look at another poll question this next one will give us a

24:39little bit of insight about challenges so please define the biggest challenge

24:45when specifying renewable systems so the second poll has

24:50fewer options to answer so if you could let us know what your

24:56challenges are that would be fantastic let’s say so far oh I got some oh yeah

25:06one jumped up here so first cost to purchase and install is the number one

25:11pet challenge about 40 of the audience has said that is

25:16number one and then number two is utility requirements that is the second biggest

25:23challenge and the third biggest is codes zoning regulations we’ve talked about

25:29that a little bit so let’s move on to the next portion now that we know that thank you

25:36yeah all right so based on the questions I got from the group going into this I

25:42feel like the best way to kind of cover everything um is to sort of do it under the guise

25:47of Soul already and I’ll cover some retrofit items and such as go forward here too but I’m gonna frame most of

25:54this conversation in and around solar ready um so the way I like to do this if I’m

26:01working with a group um a project team or whatever is answer the following questions on the list here

26:07the sort of um build some project goals that we can all agree upon sometimes

26:13like you see at the bottom here those goals might already be defined for us if it’s in um if you’re under the iacc for

26:20example and have this already requirement there or certain state requirements such as Cal green those

26:27might provide the answers for you for some of the questions already that you need to go around but you might be working on a project that might be

26:35exceeding the code that might be a net zero building and so I usually like to start with these questions here

26:42um so for example how much solar are we going to need where where is it going to

26:47go we’re going to put it how will we support that um and how can we make future implementation easier even if you’re

26:54going to do solar now like uh as the project is proceeding

27:00um you still kind of need to answer this question and then how will we get the electricity all the way from where

27:06you’re putting it to where we’re connecting it and then finally all the

27:12nitty-gritty about interconnecting into the electrical grid whether that be the code requirements or the utility

27:18requirements has came up there in the poll

27:23so how much how do we determine how much if it’s not just defined for us by the code

27:30um so again we need to first pick figure out what the what’s the energy goal for the project is it Net Zero is uh is it a

27:37percentage offset that you’re trying to achieve of the energy use of the building or is it more space based like

27:44for example in the iecc that they want you to use 40 of the roof

27:50um so if we get a number let’s say we’re doing a 15 offset or something like that

27:55then we need to sort of um know that energy amount that we’re

28:00trying to offset there so for existing buildings this is pretty easy we can use meter data for new buildings generally

28:06you’re going to have to um use uh an energy model to achieve

28:11that uh which usually spits out an energy use intensity or an eui which you

28:16can convert to kilowatt hours and get close on the size of system you need

28:23the other piece of information we need to know is how um how a system in our area will perform

28:30what what one kilowatt of solar will produce given the orientation and the location of the installation and so that

28:37we’ll need to use a calculator such as PV Watts from nrel or other software

28:44such as PV syst or helioscope as an example I have a web-based one in the upper right corner there and so this

28:50will tell us we’ll Model A system in there and it will say for every kilowatt of solar you install it’s going to

28:55produce 1500 kilowatt hours annually something like that so from that we can solve for the PV

29:02system size we need knowing our energy goal we can divide that by its performance and get a the nameplate

29:09rating ish for the system size that we need to Target for the installation

29:14foreign next we need to consider where that’s going to go the image I have here is from a site

29:21visit I did a while ago where I had a I looked at about 15 different schools to

29:26determine uh which ones we wanted to put solar on many of them were brand new and

29:32considered solar ready including this one right here and this was well before requirements were listed in the iecc or

29:39anything like that this building did not get solar because as you can kind of see my questions

29:46would be where are you going to put it the cleanest area to put an array would have been north of the penthouse which

29:51would been in the shade the entire time the penthouse is littered with a force of fall protection anchors and on the

29:59right there’s just a lot of obstructions that either cause shading or just don’t give you a good area to put solar array

30:06so the definition of solar ready for this building was literally a conduit up to the Rooftop

30:12the next building and this is kind of a spoiler alert this one was a good building sole ready wise because we

30:18ended up putting solar on it this one had a nice clean rooftop that had very few obstructions had a

30:26pathway from the electrical room up to the rooftop already appropriately sized and it made a very easy solar

30:33installation in the future so at this time when I went through this I realized that

30:38there wasn’t a good definition [Music] um for us already and then there’s a lot

30:43of room for interpretation on what that meant I think it’s getting better like I said with the iacc right now but still

30:48at some point we need to answer those basic questions

30:54if you’re looking at a flat roof with solar you’re going to end up with most likely a ballasted system

31:00um similar to the image on the right upper right there and those will be a slope between 5 to

31:0710 degrees I think I have my greater than PSI in the wrong direction there but typically

31:12five to ten degrees is what you’re going to have for the solar modules there to maximize the density of the installation

31:20because the the greater the slope there the more inter row shading you’re going to have and the further apart you’re going to have the modules

31:28um with that you’re going to end up with about 13 to 15 watts square foot so now

31:33that you know your system size number from the previous question you can kind of calculate a rough area you’re going

31:39to need to support that array again this is a balanced system

31:44um but I want I want it to be clear that just because it’s a ballasted system does not mean you’re going to get away

31:52without mechanical anchors um mechanical anchors may be required due to seismic in seismic areas due to

31:59shifting of the array may be required due to wind uplift especially in the

32:05corners of the array this is usually calculated a lot of times by the racking manufacturer I had a clients once think

32:12that he was sold a ballasted array and there would be no roof penetrations and was frustrated to see a bunch of roof

32:19anchors on there that being said the roof anchors now have been um

32:24got to the point now where like in the image shown in the lower here there’s

32:30um they usually come pre-made with the type of roofing material to match the

32:35roof of the building and so they can easily be screwed on and then welded in place

32:41um or whatever the other method that you’re using depending on the roof type so it does not mean necessarily that

32:47you’re just poking a hole in the roof it’s um pretty more like a little more sophisticated than that

32:52structural standpoint you need about five pounds a square foot is kind of the general rule of thumb from a ballasted

32:57array um to support it uh the other thing to consider if you’re in areas where you

33:04have significant snow you’ll need to worry about snow drift zones as well and during the winter time

33:14um again for the area calcs we also need to consider the fire access which Benny

33:20had mentioned earlier and that generally consists of a four to six foot pathway around the perimeter of the building

33:26depending on how big the building is larger buildings require six feet if

33:33they’re less than 250 feet on either axis it’s four you’ll need Center access Pathways to

33:38building and in addition every 150 feet square

33:43roughly you need to break up the array to provide venting opportunities in the case of a fire the image I have here is a really large

33:51building and it’s a little hard to see all the pathways but you can sort of see how

33:56I’ve had to break up the array um this example though is relatively easy it’s it always ends up being a game

34:05to sort of determine how your building fits the general guidelines of a flat

34:10roof box because many of the buildings we deal with are not that so that’s one

34:16thing to consider is no this is what the code says and kind of how that gets applied to your

34:22building that may not be a flat roof square or rectangle

34:30for a slope roof um you generally I always suggest if we’re doing a slow proof to try to use a

34:38metal staining seam roof it’s the easiest one to attach to you don’t have to have roof penetrations for every

34:44anchor which probably need to occur six to eight feet on every rail you can use

34:50clamps such as the one shown by S5 there to mount the racking through they just

34:55pinch the seam and so there aren’t any penetrations other than your electrical on that rooftop

35:02because you don’t have to worry about integral shading you can get a higher power density on the roof so you’re looking at 17 to 18 Watts

35:09um a square foot and in addition you’ll need to consider some setbacks for the

35:15ifc2 about three feet around the edges there if you’re going with carports

35:22please check your local adoptions and addendums to the adopted building code

35:28because they all have a little assumptions in here in and about the maximum amount of size the rate can be

35:34and the spacing requirements for those you may end up having to do sprinklers if they get too big and there’s

35:41different things for fire truck clearance and the light there so please check your local code adoptions for

35:47those um for solar for ground Mount again

35:52we’re going um you might be able to have a smaller array to achieve the same amount of

35:57energy production but you’re going to probably take up more area because of the row shading so you’re looking at about 10 watts a square foot

36:04um You probably have a fixed tilt maybe you can get into the tracking system um but and you also want to consider a

36:11fence around the array as well just um to keep people out of it

36:16finally where’s all the equipment going to go is it going to go up on the rooftop is it going to go on the ground

36:23Mount um and so these are just some things to to consider along with that too whether

36:29you go in the rooftop array or carports and the like so here’s a quick example calculation

36:35that I went through I have a building that’s 50 000 square feet we assumed

36:40energy use intensity of 25 so we calculate our energy energy use both in kbtu and kilowatt hours per year I

36:49modeled a couple different arrays at 5 10 and 15 degrees to kind of get their production factors and so I was able to

36:56take my annual energy and divided by those to kind of calculate the different array sizes I would need to support that

37:03then taking it from there I figure out the area I would need for the different arrays as well too with the bottom

37:12so again I’m going for this uh we want to set it for Success

37:17um don’t do that um go through and just be mindful of

37:23where you’re going to put it and um set up whether you’re going to do the solar now or in the future take all that into

37:30consideration and prepare it for an easy solar installation in the future

37:36for the electrical pathway you need to consider how you’re getting from the rooftop down to the main point of

37:41service or the point of interconnection while during the building design ideally there

37:48and then make sure your conduit is sized appropriately for the system as well this is also in the iacc you don’t

37:56necessarily need to connect all the way to the gear but at least have that point A to point B planned and likely that

38:03utility disconnect as well too so you need to kind of understand the utility requirements and where that disconnect

38:08needs to go because that’s where you’re trying to get back to also um from the interconnection standpoint

38:14this is covered in article 705.12 in the NEC I could easily spend an hour on this

38:20topic so I’m going to race through it a little bit just to give some general Guidance the smaller the system is going to lean

38:28towards a load site connection meaning you’re on the load side of your main service disconnect

38:33um and the larger size is going to go more on the supply side

38:39for the load side disconnects the most commonly used one is the 120 rule which

38:44means I can locate my service the PV point of interconnection at the opposite end of the bus bar from the main service

38:51disconnect and if I sum those two up they cannot exceed 120 percent of the

38:57rating of the bus

39:02um another way around this one is you could either upsize the bus compared to the

39:08main breaker or reduce the main breaker so it is smaller than the bus and then some of those together can be a hundred

39:15percent and then you can put the solar anywhere on that bus that you like these are the easiest ones in a retrofit and

39:22if your system size is relatively small compared to the service it’s the most

39:28easy to implement for larger systems and you’re going line side connection you’re allowed to have

39:35that PV system size could basically be up to the rating of the bus

39:40um some clients now are going so already in this fashion to where they’re adding a solar connection cabinet for the

39:46example on here to where when they install solo they don’t have to shut down their main building service this

39:53allows some other require um complications though too of what happens if your system is significantly

39:59smaller than in this example 4000 amps you’re going to have to somehow size everything down in the future

40:09and then in more of the retrofit standpoint you might have to do a custom bus tap where you drill the bus if you

40:16don’t have enough existing lugs on the um on the supply side of that disconnect

40:22and this will require a UL listing a re-listing of the gear generally and so

40:27what this will look like is you’ll probably have to go to a consultant and they’ll come out and take measurements

40:32and determine if and how that thing could be modified to supply the existing

40:39stuff and then they’ll come out afterwards and bless the work that’s been done and re-list the gear

40:46um I know we’re getting close to time here so I’m going to start burning through a couple of these other slides a little bit

40:53um finally check on your utility standards they all have something that’s

41:00um a little bit different depending on the size of the gear whether or not you need a production meter any advanced

41:06controls or remote terminal units especially in areas that are getting more heavy in solar like the Southwest

41:12so really read through their documentation and understand what they need

41:18um there to comply with their requirements finally if you’re preparing a solo ready

41:24deliverable my recommendation is again on a roof plan whether architectural

41:30electrical show the proposed area clearly you don’t have to do a layout necessarily on the electrical plans

41:36clearly indicate the pathway from the rooftop to your point of connection and

41:42also show that on your single line diagram and finally a performance spec along with that to indicate your

41:50intended function the system size and all that there you don’t need to do Full Construction draw documents because

41:56every different module and inverter combination requires its own different engineering there

42:06um quickly moving on to batteries for a little bit um there’s a lot of reasons why you

42:11might install a battery system maybe it’s a state energy requirement for example that’s coming in the next round of Cal green

42:18um and I’ll go through a quick slide of some of the different reasons why you might want to do that the industry is

42:24still young the markets are still developing in this area and codes are still moving quickly the tech right now

42:31is mostly lithium ion but there are some other options out there like Vanadium and such like that

42:37the things to focus on and batteries right now is the locations you’re putting them and the listings of the

42:42battery systems are critical so Uhaul 9540 and 9540a are the two main listings

42:49you want 9540 is really the battery system operation and fire requirements

42:55and 9540a is a flame spread test that you’ll really want to have if you’re

43:00going to be in around on or near a building um right now the IFC and the NFPA 855

43:09are the two codes that are kind of bouncing back and forth along each other to trying to build the requirements they

43:15vary slightly but they’re usually kind of incorporating each other’s ideas into that over the long run

43:21the handful of different reasons why you might want to use a battery system there’s a lot of information on the

43:27slide and I hope you’ll have a chance to look at it all later um but it might be for resiliency if you

43:34need to maintain a microgrid in case of power outages again if you’re in the Hawaiian Market or somewhere similar

43:39where you’re not allowed to backfeed the grid you need to use Battery Systems to store that excess produced by our solar

43:45system during the day and discharge that at night if you’re in an area where you

43:50have great demand charges at certain times a day they’re going to be in the demand management column here where

43:56you’re charging at night time and then discharging during the day to lower the peak demand of your building when rates

44:01are really expensive demand response is similar to that it’s just maybe your utility has a program that says turn it

44:08on now we need your help and finally I have carbon Arbitrage sometimes it kind

44:14of goes hand in hand with demand management but there might be times a day where the carbon

44:22um the amount of carbon per kilowatt hour is greater and you want to reduce your carbon footprint so you might

44:28charge the batteries when the carbon is low and discharge when they’re high

44:35an example of how this all plays together if you were to tie this together in a net metered system this

44:40here assigns for a on basically a Net Zero Energy building

44:45the red curve I know it’s a little tricky to see with it all going on at once the red curve here is the existing

44:51building demand over the course of a day if we add Net Zero solar in here that’s

44:58the pink curve and how it produces the energy there this is actually in the

45:03California Market where right now the peak demand time is not during the middle of the day anymore because of all

45:09the solar bits in the state they’ve shifted that now the evening from 4 pm to 9 p.m which is this yellow rectangle

45:16so really um you see that solar does not do a good job of of assisting in reducing your

45:23demand during that time frame anymore it drops off to zero during that time so that’s where the batteries come into play the blue line is the battery

45:30function there where we’re charging at the left of the screen in the green area in the middle of the night and then when

45:37that we hit that um on Peak window there the batteries start discharging to help assist the

45:43demand lower even more and the net result is the green curve

45:48and Sean uh when looking at Zero Energy buildings and sizing these arrays you

45:55have to understand what those loads after hours are too a lot of buildings when you get in the commercial realm aren’t necessarily nine to five you

46:01might have a refrigerated uh facility or you might have something with 24-hour uh

46:07operations data center like a mission critical facility to size those for Zero Energy you have to have some significant

46:14overproduction during those peak hours to be able to to handle not just the the shifts at the evening in the morning but

46:20also overnight yeah thanks Benny yeah this this curve here is a pretty simple building it’s an

46:27educational building which is no one’s around in the evening and everyone’s around during the day but um yeah thanks

46:33that’s a great Point Benny um finally um in a microgrid scenario again I could

46:40probably talk a whole presentation about doing microgrid setups um again I mentioned about the grid

46:48following and grid forming in the microgrid we need to have a grid former as we disconnect from the grid and

46:53isolate the building or portion of the building and generally that’s usually been the best system maybe you have a

46:59generator that does that and the other thing I’ll talk about here is grounding

47:05and that’s uh make sure to keep track of your system grounding much like you do

47:10with the generator whether you’re doing three pull or full four pole switching

47:15to make sure that you maintain a system ground I’ve seen issues before where

47:21that’s not been maintained properly and so there’s been some issues with some single phase loads

47:27usually in these scenarios the controls are done by the best manufacturer or

47:32assembler um and so when you’re designing these many times I’ve mostly just written a

47:39sequence of operations and coordinated with at least the basis of design manufacture for the system to

47:45put that together but usually the best manufacturer is packaging up that system

47:51and providing the control system um coming near the end here uh just a

47:58quick slide on costs these are rough ballpark costs that I’ve seen in the

48:04market lately for the cost of building the systems rooftops are coming in uh

48:09275 three dollars a watt your carport arrays are more expensive because you’re building more structure to support them

48:16canopies this would be something similar to that but maybe on top of a parking garage where again you probably have

48:22even more structure and ground Mount arrays are generally the cheapest right now

48:28um the battery energy storage systems they’re estimated I I might even say this is a little bit a year old now I

48:36think about a dollar per watt is really plus or minus is really what they’re kind of coming into right now but it

48:42also really depends on availability like I said the market is still young then you want to cover the PPA

48:49yeah thanks Sean so there’s lots of different ways what Sean’s talked about could be applied to

48:56the design of it but how do you actually purchase it who owns it who puts it on the building so we see the purchase

49:03where you purchase the equipment you design it into the building you put it on your building you’re maybe taking

49:08advantage of that I mean the federal tax credits and rebates local incentives

49:14from a utility company but then there are other options where someone else who owns the array can lease it back to you

49:22and that’s probably one of the least common but then one of the more common ones that we do see is a purchase power

49:27agreement or PPA these are typically over um the 25-year life of the solar array

49:34and it’s worth a third party actually owns designs and installs this and sells

49:40you back the electricity at a different rate so pretty much you’re putting a utility on your building

49:47um but you’re not responsible for the upkeep of it the maintenance of it and you’re able to take advantage of the use

49:54of that so the purchase power agreement is certainly something that we see applied when it comes to people who want

50:02to uh take advantage of putting the equipment on their building but not necessarily have the responsibility for maintaining

50:09it or operating it and can take advantage of the reduced utility rates but the the purchase is one of the most

50:16common one we mostly see people purchase these these arrays but the PPA is certainly another big option out there

50:29um and finally um I get a lot of questions about maintenance and lifetime for these

50:34systems right now most PV modules are warranted for 25 years but they’ll probably produce much

50:41longer than that if you let them they usually just degrade about 0.35 to 0.5 percent a year in the their amount of

50:47production so 25 years usually ends up being well I think 20 years is 80 there

50:54um standard warranties for inverters are 10 to 15 years they can be extended but

51:00here’s the electronic piece in the system and we know Electronics do have a lifetime so for example most ppas factor

51:07in if an inverter replacement about halfway through the agreement period if it was say 25 years and for battery

51:14energy storage systems they’re usually warranted for about 10 to 20 years too depending on that and so if you were

51:21going for a full 25-year PPA for example there might be a battery replacement worked into that too but many of them

51:28are warranting their systems for the full 20 years so your maintenance on the system again

51:35inverter battery replacement you might have to replace failed modules every now and then cleaning the modules to

51:42maintain your max production is something that’s uh would be done frequently and then anything else would

51:48be anything to do with the communication systems for metering the system whether

51:53that’s wired or cellular and potentially anything to do with the thermal management system for the best although

52:00that should be covered under the best warranty if that was going to be the case I think that’s about it

52:08yeah nice thank you Benny thank you Sean that is a lot of information to take in

52:14and as a reminder you may earn one AIA CES approved learning unit for this

52:20event you do need to pass a 10 question exam and to take that exam you can

52:25access it under the learning unit exam tab it is at the top of your screen and it

52:31does open in a new browser window and quickly just wanted to let you know that we have more education a course just

52:37started yesterday on how to engineer for Future Ready Healthcare building so

52:43check it out very related all right gentlemen we are going to take some questions we have quite a few again

52:49if you do have a question you can direct it to one or the other presenter

52:54um but Benny I’m gonna start with you all right so electric boilers is really

53:02what we specify for renewable since we buy renewable energy credits for our

53:07electric power purchases could you comment on that Benny

53:16hey Benny if you can make sure that you are off mute yeah we can hear you thank you all right could you hear me better

53:22uh sorry about that the uh yeah the the how you you know if you’re gonna put renewable energy on your building it’s

53:28typically going to be Electric solar is producing electricity so having a natural gas source of heating is

53:35probably not going to be your most uh best way to offset uh reductions so as

53:40we look at you know Carbon reductions carbon neutrality designs towards that you’re uh you’re going to want to be

53:48putting electric equipment in your building to offset that and so yes you know electric boiler is a good option

53:54um you know they’re they’re they’re probably you know not the most energy efficient

54:00because they’re you know 100 percent uh effective at producing electricity as opposed to something like a heat pump uh

54:06that could produce two or three times as much uh heat per unit input so you know as we look towards carbon reduction and

54:13solar designs we’re going to want to put more uh designs on that have efficiencies like a heat bump so I think

54:18that’s where designs are starting to move towards okay great got it and if you do have

54:24questions please type your question into the ask a question box and type the presenter’s name so we know who to

54:31direct it to as a reminder you can download the presentation slides in the

54:36event resources tab on the left side of your screen so Sean I’m going to direct this next

54:42question to you um we’re talking about IEEE 1547 requirements here so what are those 1547

54:51requirements for interconnection and common utility requirements

54:57so I’m going to pair that IEEE 1547 and

55:03UL 1741 are roughly I think they are pretty much

55:08the same thing in terms of requirements and generally a utility is going to require that your inverter whether that

55:16be for your solar system or your battery system or wind system has that listing

55:22there um because that basically tells them it’s safe for grid interconnection

55:30and the main things that covers is there’s protection scenarios in there

55:35for the current and over frequency and under frequency and the whole Gambit of those different protection scenarios are

55:42very well spelled out in there and there’s a few other things in there such like a a nitribly 1547 inverter must see

55:52the grid for five minutes before it can interconnect to the grid and then if the grid drops out it’s got

55:58a disconnect immediately and stay off until again it sees a stable grid again for five minutes so there’s operational

56:05stuff and protection schemes that are spelled out within that but generally if you’re doing grid connected you want to

56:12make sure you have that UL 1741 which encompasses those IEEE 1547 requirements

56:18in it all right thanks for that info um Benny another question over to you

56:24what’s the physical dimension of a typical solar panel

56:29well it’s going to depend on what type of solar panel you go with they can come in a variety of different sizes and if

56:36you’re going with a thin film panel you can design it to be whatever size you want when you go to more of the mono or

56:42polycrystalline style they tend to be uh have historically been around five foot

56:48by around three foot or so 18 square foot in dimension but lately we’ve

56:53actually seen the 540 watt panels uh closer to like a 28 square foot and

56:58again the dimensions can can be all over the map on that but they’re getting much much larger as a single panel like a

57:04single panel of 540 watts is pretty impressive on a commercial scale

57:09right yeah it is thank you all right Sean another question for you um so this

57:15kind of goes back to what you were discussing toward the end of the presentation are you saying it’s a good idea to charge batteries at night from

57:22The Grid rather than during the day what what are the pros and cons there I the example I gave and I did go

57:30through it very fast was a specific example um where the energy is really expensive in

57:38the evenings where solar is not helping you offset that energy

57:44um and maybe I guess and the energy is still I guess

57:50a little bit more um is cheaper at the evening so it really depends on the rate structure of

57:57your utility there it’s going to be different everywhere I’m looking at a similar thing right now and

58:03um the example I showed was in California I’m looking at another area and that doesn’t California’s example

58:09does not work at all in the other area it’s completely different so it really just depends on what the rate structure

58:15is of your utility um and again exactly what you’re trying to accomplish there whether it’s a zero

58:22feed in where you’re going to be charging that with the solar during the day or maybe you’re just trying to put

58:27batteries in stand alone without solar to offset your demand at which time you’re charging at night

58:35sure okay got it um it looks like we have time for just one more question and Benny I’m gonna

58:41send this one over to you is the PV Market experiencing supply chain issues

58:47and what kind of delivery times are you seeing with us yes that is correct the supply chain is

58:55having delivery issues this goes to a fair trade uh lawsuit that’s under

59:00investigation right now that is uh scheduled to be determined sometime in August I don’t know if that’s going to

59:06get expedited due to some complaints but it is certainly halting a lot of projects or putting things into place

59:12but it depends on where you’re sourcing those materials from we’re still seeing delivery times in the six to eight weeks

59:18range currently depending on people are sourcing it from a U.S manufacturer or Canadian manufacturer it tends to really

59:25be affected mostly the Southeast Asian manufacturers which are by and large a majority but we’re still seeing people

59:32able to Source things and the costs haven’t been able uh or haven’t been escalated as such but I think that’ll

59:39that’ll probably change if this uh this review doesn’t get expedited a little

59:45bit right right okay well lots of great information and definitely not enough

59:50time um I would like to thank these extraordinary subject matter experts

59:56Benjamin Skelton and Sean Avery for sharing their extensive knowledge of

1:00:02Renewable Power Systems and now we do want your feedback to improve future education sessions a couple of questions

1:00:09will pop up on your screen as soon as this webcast ends please take a few

1:00:14seconds to answer them and finally on behalf of Consulting specifying engineer

1:00:19and CFE media and Technology I’d like to thank you for joining us we’ll see you

1:00:24again at the next education session thank you and goodbye

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