 Hey Aloha and welcome to Stan Energyman here on Think Tech Hawaii. I'm Stan Osterman as usual coming from the sort of rainy mighty megalopolis of Kailua Hawaii. It's not as pretty as the picture behind me. We had a lot of rain the last couple of days. Kind of typical moving into the freezing winter of Hawaii which will drop us down into maybe 65-70 degrees here you know so we'll have to bust out the parkas. Anyway thanks to everybody this morning at the Renewable Revealed Hawaii Forum I thought it came out really well and we talked about microgrids and disasters and I wanted to continue that theme today and talk about microgrids on my show. So my guest today is from the Northwestern US and he's got quite an extensive resume in microgrids and control microgrid controls and and things like that. So I wanted to keep the discussion going and today maybe get it more into a personal level or a practical level of how you would what things you would consider building a microgrid especially on a residential area a residential you know structure maybe a small business. So today's guest is Gary Calderon and he's going to be joining us from this around Seattle right? That's correct. Oh and then and thanks Gary thanks for joining us today especially on fairly short notice I just met Gary last week via another gentleman Bob who was interested in some of the things we're talking about on this program so just timing worked out well and I'm glad you could join us today so could you start off by telling us a little bit sharing with the viewers a little bit of your background. Your resume is pretty extensive so if I read it we'd be out of time on the show you can consolidate a little bit and give the folks some of your background. Absolutely so background, electrical engineer out of UC Berkeley computer science as well also MBA out of San Francisco and more recently Lawrence Berkeley labs on San Jose State put a program of masters of science and engineering for battery battery technologies. As far as employment I'll just talk about the last 10 years prior to that it was more high tech with Sun Microsystems IBM Siemens Medical and about 20 startups and Silicon Valley but about I say 10, 11 years ago started actually installing solar for a non-profit that helped let's say a lot of the residential areas in the San Francisco Bay Area the disadvantaged communities got solar installed for free grid alternatives is the name of the non-profit headed up by two Stanford grads and it's going strong today and then since then that experience I went to solar city for a few years at the same time I was working at the factory at Tesla over in Fremont California so the whole Bay Area Bay Area was taken off on the solar side of things in addition to that I started my own company that built micro grids and also electric vehicle charging not only for residential but actually primarily like business parks and things like that the focus on micro grids was the fire stations and around emergency facilities that's where we started battery and canopy you know solar for parking lots started working at Tesla at the actual factory selling both EV EVs or the transportation electric vehicles as well as the solar and batteries for about eight years there but had moved up to the Southern Northwest to Portland and did Seattle and more recently had become a consultant for a lot of projects micro grid projects as well as not just for resilience but for what we call distributed energy resourcing and we have all these resources that come together under one umbrella and you can actually manage all the electrons where the load is heavier and so resilience of course is part of that but also load shifting and a few other things like that but what you can do in your home too which I do with my solar installation from Tesla. All right thanks one of the takeaways I got from this morning's discussion with renew rebuild Hawaii was that locating micro grids in a region the location is important for survival reasons and things like that but one of the other reasons is you know you talked a little bit about distributed generation or being able to to you know use the power from your solar writing in your house and then maybe even share it and and the thing that struck me was most of the utilities want to put the micro grids near their near their generation and or run power to a micro grid from their generation and really when you get into the nuts and bolts it's better to have the generation where your micro grid is so using renewables and such and of course most power companies are set up with a centralized generation plant going out through high voltage wires to substations from substations down to transformers and into buildings right and and so the real takeaway from that I got from this morning from most of the micro grid people was you're better off consolidating generation right where your micro grid is and using it which makes sense there's no line loss you don't have if you have hurricanes and things you don't have those poles and stuff knocking wires down and having to recover from that right so in in that light let's focus on your house and why don't you kind of walk us through your house a little bit and then I'm going to ask you some more specific questions about decision points and designing your micro grids okay if you wanted to start with just the pictures I provided we could do that too but at a high level I do have batteries not just for resilience here or backup this is the installation here in my garage so you're looking at two batteries there that's close just under 30 kilowatt hours combined with that and to the right you see my Tesla EV charger and then with considering this combination there's still some answer I mean you still need to tell the installers or whoever you're purchasing from whether or not you want just critical loads it could be medical equipment only or your servers whatever and maybe a few lights when there's an outage I chose to do a whole home right which would take my whole entire service panel and back that up so I so far and it's going on two years right now I've had about 20 outages right the software that's provided with most of these installations allows you to sort of break out what you want as far as percentage wise maybe I'm going to 50 50 50 percent of my let's say excess solar stored in my batteries can be used for a potential outage the other 50 percent could be used for nighttime use once the sun goes down so I have control of that right the other thing that you mentioned is sharing electrons so I also had that option with the utility when the utility for example in this Seattle area we had like 110 115 degree um uh weather for about one week right nobody was prepared for that from coming from California I have air conditioning and a lot of people don't right so they weren't used to that so they would they could if they wanted to it's giving me a call say can you offer some kilowatt hours from your battery that's called demand response so that's another thing I signed up for to help my neighborhood in case there was outages or just not enough generation right so is that a is that arrangement with the utility something that comes out of a public utilities docket and and it's set up so that there's a formal agreement between the homeowner and the utility in terms of how you share things yes Stan so I wouldn't say every utility would do that but uh Puget Sound Energy which is my utility I used to have PG&E and San Francisco Bay Area but they do it too so this is helping the community right so helping it become resilient not just your home but now can you really afford it so you just got to look at the the actual kilowatt hour stored well I might want to just keep it from my family because I have maybe medical equipment or some other things so I may not sign up for that but that's what most residential today not back in the day but today more people are getting the battery solar combination for the reason of for example for the last six months I haven't paid for one kilowatt hour in the Pacific Northwest with my system which is actually uh pointing southeast so in the summer we have longer days too but um so I get a lot of solar in the Pacific Northwest I did a lot of convincing when I was selling in Portland in Seattle and but it works so how many how many kilowatts of solar panel do you have on your roof so I had just about eight kilowatts oh yes that's a pretty sizable amount here in Hawaii just for your to comparison but when we're when we're estimating usage we we estimate that we have about five and a half hours of rated power a day from our solar panels just to because in the morning and afternoon it's not as good plus sometimes you're you're got cloud cover you're up near the mountain so you might have trees or you know near your house or whatever and and so you know but when you when you do that calculation or when you did the calculation for your house you obviously had to take into account your tesla charger um I mean that you're charging your car that that takes quite a bit of power off of your your micro grid um and then and then you say your houses your whole house is powered by your your solar panels where you you said that the electrician could basically take critical circuits or whatever circuits you want and divide them up but how did you just kind of walk us through your logic of how you calculated you needed eight kilowatts of power on your roof well typically you're going to give them a year's worth of your electricity bills right right electricity bills pretty much dictate uh how much how big of a system and then you're also you're looking at not only roof size but you know some areas you have these fire setbacks your roof could be pretty big but the fire setbacks could be three feet from you know from the the edges of the roof to allow the fire department cases of fire to walk around so that takes a little bit of your real estate sometimes a lot so in my case um I was able to get those two raised um on my to come up to about eight kilowatt so they indicated about 80 percent of an offset meaning that 80 percent what the size system I chose about 80 percent of my um energy would come from the sun per year so and it depends that's only counting if I if I didn't use the batteries right if I only use the batteries for resiliency and just sitting there stored and not being used in the evening then that would be 80 percent but I I think I'm pretty much net zero right now so those are the decisions you may only want 50 percent you may only want 25 percent I had people sometimes they don't want it but they end up with it because of the shading conditions especially in Pacific Northwest and roof right orientation and size so those are the components those are the things that the engineer looks at so they look at trying to achieve your goals first if you can get net zero right a hundred percent of your you know your electricity coming from the sun annually they'll go for it but it's not always possible but I'd say 70 to 80 percent is typical when people satisfy with that so do you recall what your average daily use was for that house before you switched over to solar um I would say I do have 30 something kilowatt hours 30 something or 40 kilowatt hours it was just under because I had um because I had daughters right so moved they moved out they like hairdryers and they're like yeah oh yeah that all adds up yeah so they had left so for college and stuff like that but what I would say is probably maybe 15 uh thousand to 1500 kilowatt hours right um a month okay and then of course I had air conditioning so that would go up uh during the summer months right um so we looked at that um I'm not too sure if I'm prepared to show maybe uh one of my bills or six I think I had six of them prepared but showing the difference of and of course we're looking at this geography right not Hawaii but looking at the city northwest where I'm pretty much in the last six months haven't paid a dime for us a kilowatt hour so here it's illustrating on the left hand side it was the past year and then since having solar on the far right it's showing a lot less and as you go down on the bills you'll start seeing that it's close to nothing now this year is even even less right that's after the first year so it does work I mean in a lot of cases you have a lot more sun than than we do right now it's like raining every day for the last four weeks and but it's constant rain it's a real winter and sometimes snow right so yeah well you were going through your bills that I busted out my calculator it looks like you're you're averaging between 45 and 50 kilowatt hours a day uh average for your your um usage with your daughters and their hairdryers and stuff so you're probably down around 40 with eight kilowatts of solar on your roof um you're about like my next door neighbor who has almost your identical system has two tesla power walls and he has around I think 30 between 35 and 40 basically kilowatt hours of production available every day so that's probably around seven or eight kilowatts of PV panels based on our solar so from from my perspective what you generally do is like you say you start off with your electric bill you you estimate your usage you kind of anticipate future use like you're going to get an electric vehicle or you know you know maybe you're doing more work from home or something so you kind of throw that in and maybe even you minus some off for led lighting and you know things that don't take as much power and try and get as good an estimate as you can um I generally recommend that you kind of overproduce solar just a little bit especially with store and I don't I don't recommend anybody get solar without storage for me if you don't get storage it's really you're you're just selling yourself short and you want to talk about that from a homeowner's perspective yeah so a lot of people think they will still have backup right or resiliency just by having just solar right solar panels solar arrays and okay I have backup I've talked to many many people and they oh I've had solar for a long time I don't need a battery add back I said no you don't you don't have backup and in fact when there's the lines are down or somebody's on the lines troubleshooting the inverter is disconnecting right you're sort of islanded from the grid until that's fixed and they reconnect you so that's one thing you have to make clear to people that you don't have backup with the batteries you you will be able to use the batteries you're still disconnected from the grid when there's an outage right so you don't let you keep somebody that's troubleshooting on the lines and your solar is working for you as long as the sun's out right but your batteries the power source are the energy source right now so generating that solar during the day it will still continue to charge your batteries so that's like a virtual power plant if you will that's what I call it you have your and you don't have to it's it depends on the software too you can't physically island right once you're connected to a utility at least in these parts I know in California Oregon and Washington on the west coast here I don't know what Hawaii allows you to do if you decide to go off grid but that's the case here so it's hard to disconnect from the grid um yeah especially once you connect to the grid um so so let's kind of walk through the system and this is really basic stuff for you but yeah the solar on your roof you calculated how much you need it's up there it produces DC electric power that comes into a controller that charges your battery and and and sends power either to your inverters or to your battery depending if you're charging your battery or running your other system right so if once your batteries are charged it cuts off from the batteries and and it's going just to the here your inverters your inverters then change the DC electricity to AC power right so it can run your all your household appliances and things like that um and those control items are important too and depending on whether you're like you say if you're off grid you probably have choices of voltage whether you want to stick with a real basic 12 volt or 36 or 48 volt but those tesla walls what do they basically run at voltage wise are they 48 volt well they it's a DC coupled right it's not ac coupled like okay one thing is that the micro uh the micro grid inverters that are back those instead of your central inverter that uh some people you know it depends on a lot of people think it's uh advantageous to have a micro inverter behind every panel right okay that's ac coming off that okay so now you need an ac coupled type uh power wall inverter right i should say and so over the central like i have the the centralized type of inverter is DC coming off the roof it's converted to ac and now that's charging um my inverter internal of the power wall right and so there's really everything's regulated so it's not you you don't really have to look at uh voltage 12 24 48 that's already built in right and it doesn't have to be tesla inverters i mean the inverters that are used right now i mean um there's a variety of them that work very well you know dc that and a lot of its solid state right so it's not like the old versions that were 150 pounds to install which i was that was very hard to do by yourself but today there's a lot that's a data logger as well so that's collecting that information another point here i want to make is that information in the in the solar inverter is collecting data continuously allowing you to view real time on your phone what's going on but also in the case of uh sun run tesla and a lot of other um let's say solar uh providers or solar pv installers they'll provide you with software to allow you to you view it let's say real time 24 hours a day and for them to also be able to troubleshoot and view it too because they sign a contract with you right in most cases a power purchase agreement could be a lease and could be just an all-out purchase so they have uh regarding the contract because i know i'm looking at the time to make sure we have enough time because this is important too um they're promising so many kilowatt hours for 20 years for example if it's a 20-year contract or warranty i should say and there's degradation that happens over the years because of the sun right this beating down on it uh some more than other environments right so they have this whole table of what they're promising as far as generation and degradation on those panels and the other hardware um so it's important to note that to understand that because some people don't look at contracts that closely or don't understand them and don't ask questions so it's very important to look at those tables and see oh 10 years from now if i'm getting it's a half percent degradation on my panels wow that's going to go down five percent or wow in 20 years it's going to be that by that time who knows they may not be living there but they need to know the next let the next homeowner understand that contract especially if it's a power purchase agreement it has to be transferred over to the new homeowner right if it belongs to the house or installs belongs to the homeowner the current homeowner that's part of it just like the kitchen sink is part of the sale right yeah a lot of people like to opt for the power purchase agreement for a couple reasons number one it's usually much more affordable because it's more like just paying the utility company you're paying the power purchase company they they still they own the equipment on your house and you're just paying a monthly bill for electricity exactly and they're doing all the everything right now let's say after and in the case of my my purchase power ppa's i should say power purchase agreements when i was with solar city after about five years you were able to purchase you had the option to purchase and own that system so um and that's something that needs to be reviewed at some time because a lot of times it might take uh 30 to 60 days maybe longer to install these and people just anxious to get it and they'll start signing things and everything's online and they won't pay attention to the warranty which is very important so uh that's that's a heads up for anybody listening well speaking of warranties you know one of my observations is there's there are a lot of people who are really afraid to not be grid tied you know like they would never go off grid because it terrifies them to think they're responsible for their own electricity but the equipment is actually pretty reliable and as long as you understand the degradation of the solar and the batteries batteries degrade over time as well um how much you know in terms of daily maintenance or monthly maintenance or annual maintenance really is there that much to do with your system the only thing I could think of especially in parts where you have a lot of trees like Pacific Northwest uh sometimes they have moss sometimes they have uh branches or you know just needles piling up and things like that and they do get a little dusty I mean I would never suggest somebody getting on their roof and start spraying them down but maybe hire somebody but it's it's it's a little dangerous just to be on the roof not in the solar but whether without solar so I quite often I ask do you have you know sort of a dusty area dusty roads or trees hanging over and parts of your your roof because the dust is going to cover that they'll be more efficient if they're just just spraying them off you don't have to scrub them so um as far as the other maintenance on on the hardware you saw in my garage that picture that you don't need to touch anything if something goes wrong let's say I'm up with my batteries within those two enclosures there is on the top half the inverter right if you were to open that up in the bottom then you have your batteries right your battery cells and remotely they can actually test things so in the case of Tesla and I believe with others and the competitors they're doing upgrades remotely like they do with their electric vehicles right you're not saying yes or no to an upgrade they're continuously upgrading remotely through the wi-fi of your home right so I would say in almost all cases you're going to need some type of internet connection wi-fi they'll give you a router so they can monitor what's going on and they've contacted me too saying hey something's wrong with your router hey something and via my cell phone right they'll text me and something and so they're on top of it they have these alarms going off with other installations so it's come a long way as far as pricing it looks like we have three minutes here as far as pricing of solar panels I've been doing it for over 10 years right and I believe when I first started per per watt to install it was closer to like eight nine dollars per watt so the prices have come down considerably and closer to a buck fifty right per watt per installation of solar the other thing is administration today is uh continued the 26 federal tax credit not just for the solar but for both solar and battery and if you decide to get the battery at a later date uh within the next two years you're also as a retrofit get your 26 federal tax credit once that battery is installed so it's a pretty good opportunity to to go after solar if um if it's something that you've been looking at and waiting for prices to go down well that's uh that's a pretty good place to wrap things up here because uh believe it or not we we have hit our our time limit but um I'd like to say just for another uh piece of confidence builder if you're thinking of getting solar do a good job work with a good company consider a power purchase agreement if you're especially if you're a little nervous about maintaining some of your own gear and by all means get battery backup good advice great advice okay well gary thanks so much for joining us today and um you know we'll talk to bob and maybe have both you guys back on another show and talk a little bit more about um micro grids and more detail so thanks for being here and um until next tuesday to all the viewers stan energy man signing off aloha