NeilBlanchard
Posts: 298
Joined: Sat Feb 21, 2015 12:19 pm

Solar PV - Save Money & Shrink Carbon Footprint

Wed Mar 21, 2018 8:46 am

We have been driving EV's for 3 1/2 years, and we are now using a heat pump for most of heating our house, as well. We got a solar PV system installed yesterday, and it should soon be generating a large amount electricity, to offset our use. The system is Sunpower 327 watt panels (about 20% efficient), and it is warranted for 25 years. The system will pay for itself in just over 5 years, with all the incentives, and in less than 10 years without them.

It is a 10kW system on the AC output, and the estimated annual output is just under 13MWh.

We have expensive electricity here in Massachusetts - we pay between 18¢ and 22¢ total per kWh (both generation and distribution costs); and we also have chosen to pay another 2.4¢ / kWh to support renewable generation. Even with these costs, driving our two EV's (Bolt EV and e-Golf) cost us only about 4.5¢ / mile.

Here's the roof panels, on our reconstructed roof (which is still in process):

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And the equipment in the basement:

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I am really looking forward to our reduced electric bill, and our reduced carbon footprint.
Last edited by NeilBlanchard on Fri Mar 23, 2018 12:16 pm, edited 1 time in total.

dustboy
Posts: 50
Joined: Wed Nov 08, 2017 8:10 pm
Location: SF East Bay

Re: Solar PV - Save Money & Shrink Carbon Footprint

Wed Mar 21, 2018 8:35 pm

I am considering the solar road as well, as our power is similarly expensive. But the solar plans (read: scams) are confusing as heck. I would consider buying a system outright and installing myself, but I don't think we would see the ROI before we sell the house. Financing is just another debt trap, and it seems like the leasing deals are sketchy at best...we would rather stick with the devil (AKA PG&E) we know.

We are still on the fence, I drive a lot for work and it would be nice to have those miles be CO free...but so far I don't trust the solar deals that have been offered.

Because we charge at night and barely use power during the day (when our solar array would be generating power), most of the actual power for the EV comes from the grid anyway. If we can close the system with a storage battery, then that starts to make sense, but again the ROI is a long way out.
2015 eGolf SEL -- Passes everything but a charging station!

miimura
Posts: 1317
Joined: Fri Mar 27, 2015 4:13 pm
Location: Los Altos, CA

Re: Solar PV - Save Money & Shrink Carbon Footprint

Thu Mar 22, 2018 1:31 am

I have a small solar system (4.3kW DC) and recently got two Tesla Powerwalls installed. When the cars are charging they do not take any energy from the Powerwalls. In theory, you could do it, but a normal Powerwall installation does not measure and offset any circuit that is outside the Backup Gateway. All of my big circuit breakers (50A EVSE x2, unused 50A range socket, unused 30A dryer socket, unused 40A A/C circuit x2, bathroom tile floor heaters x2) are still in the main panel and are not backed up or offset by the Powerwalls. In an emergency, I could charge the cars from 120V plugs in the garage if I could spare the solar energy while the grid is down. In the dead of winter, my solar only generates 5kWh/day, so there's really no energy to spare beyond keeping the lights, heat, and fridge on.

The Powerwalls are very good at eliminating Peak period energy usage in addition to the backup power function.

Our area also went on a CCA, Community Choice Aggregation, plan. The CCA buys power on our behalf to be delivered by PG&E. Their default is 100% Carbon-Free electricity and there is an option for 100% Renewable energy for $0.008/kWh extra. So, even when I am charging my cars from the grid, that usage is at least offset by carbon-free energy.
2015 e-Golf LE (returned) | 2018 Tesla Model 3 LR | 2012 RAV4 EV Shoreline w/JdeMO | Leviton EVB40 & Jesla Home Charging | 4.32kW Motech/Enphase PV + 2x Powerwall 2 AC

NeilBlanchard
Posts: 298
Joined: Sat Feb 21, 2015 12:19 pm

Re: Solar PV - Save Money & Shrink Carbon Footprint

Thu Mar 22, 2018 10:04 am

Can you folks see my pictures?

I am glad to hear about your experiences. Solar PV will save you a lot of money, and I don't know of any other way to get your money back so quickly. And yes, leases have gotten messier. But, I think if you find people who are leasing, you can figure out the legit companies.

miimura
Posts: 1317
Joined: Fri Mar 27, 2015 4:13 pm
Location: Los Altos, CA

Re: Solar PV - Save Money & Shrink Carbon Footprint

Thu Mar 22, 2018 11:15 pm

Your pictures were showing up yesterday, but now they are not.
2015 e-Golf LE (returned) | 2018 Tesla Model 3 LR | 2012 RAV4 EV Shoreline w/JdeMO | Leviton EVB40 & Jesla Home Charging | 4.32kW Motech/Enphase PV + 2x Powerwall 2 AC

NeilBlanchard
Posts: 298
Joined: Sat Feb 21, 2015 12:19 pm

Re: Solar PV - Save Money & Shrink Carbon Footprint

Fri Mar 23, 2018 12:17 pm

I fixed them, now.

Rsolaregolf
Posts: 127
Joined: Tue Feb 23, 2016 5:50 am

Re: Solar PV - Save Money & Shrink Carbon Footprint

Wed Jan 13, 2021 12:14 pm

We've had our AllEarth solar tracker since 6/15. It's rated at 6.8kW and produces +-10K KWH/yr. We only have a $30 connection fee with our electric coop and that is mostly offset by REC payments we get each year and net metering. We generate usually about 2k KWH surplus each year even with a heat pump, hot tub, etc + our EV charger. Even in cloudy northern NH it makes sense. We didn't have the option of a roof mount due to the orientation of our house.

We had a 2015 eGolf SEL for 3 years but my wife just didn't lie the lack of range in the winter. In March 2019 we traded it for a 2018Volt. That gets about 70 miles in the summer on local 2 lane roads, about 50 in the winter.

Solar installations in our town aren't taxed and so we are only about 2.5 years before our ROI is met. Another plus is once we decide to sell it's a great selling point to not have a utility bill. If you can go solar, it just feels good!

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