I've been looking into this a little. It's cheaper if your not using batteries and are tied into the grid. This might be necessary anyways depending on home layout and appliances. Your existing electric panel should need minimal alteration since they typically put a power management switching box in (forget the real term) similar to some generator setups, plus other things like an inverter. That will determine what sends power to your main panel and if any electricity is sent out to the grid.
For example, my 2 story house doesn't have enough roof space to fully run solar. This is in part due to the fact that everything is electric - heat pump, stove, water heater, etc. So it would make more sense to sell it back to the grid rather than use a battery since I need to be tied into the grid anyways.
Personally, I would want to own things that are a significant part of my house, but other people may feel differently. I decided not to do solar because there is not enough benefit to it in my situation. The grid is increasingly moving to renewables since they can bid the lowest. This will continue to push prices lower, thus reducing the incentive for private individuals to assume the purchase, installation, and maintenance costs (or lease costs).
That’s helpful to know about the minimal alteration to my existing panel, the costs of upgrading even just that can be significant.
We also have a lot of electrical appliances and I wonder if my situation might be similar in regards to whether a battery or two would make sense financially. However, one of my goals is to have more of a backup situation in case of power outages on the grid so I may be willing to pay more for this capacity.
Yeah, it could be good as a backup. I got a small generator and installed an interlock in the panel for about $500. It's enough to run important things sporadically like the refrigerator and microwave, or can run 2 space heaters. Not perfect, but would get us through. So far we haven't had to use it for the 3-4 years I've had it (other than maintenance once per year).
I got mine installed in northern california in 2019, I would have liked to go with Tesla but they were too expensive at the time. When I looked again last year, they actually looked a lot cheaper than everyone else. I think we paid $2.75 / watt. We used energysage to get and compare quotes, and there is a lot of other useful advice on that site.
In Cali there was also some issue that the rebates for each Tesla powerwall were somehow distributed per company. So if we bought the Powerwall directly from Tesla, we wouldn’t have got a rebate because they had run out, but other installers could still supply the rebate.
The Tesla software to monitor the solar generation, battery use and home energy usage is really nice, certainly much better than the “enphase” software that came with the solar panels and inverters.
Add me to the list that recommends Energysage for a basic rooftop solar resource.
You didn't mention your state. The regulatory environment differs significantly between states, and determines what the electric company can do, since they're generally state-regulated public utilities. If you can sell excess electricity back to your utility at retail rates, it makes little sense IMO to buy a battery. However, if the utility will only pay wholesale rates for your excess, a battery can be cost effective, depending on your daily production/use cycle.
Also look up "solar value deflation" and understand that, as more people install solar, the value of it will decrease as net metering regulations and connection vs. distribution costs get shifted. Read up on the difficulties people with solar leases have encountered when trying to sell their home. For that reason alone, I'd recommend buying, even if it means a second mortgage or HLOC to pay for it.
I'm personally holding out for more efficient panels, cheaper batteries, and home-scale bio-fuel production for excess energy so I can size my install to support being truly off-grid throughout all four seasons.
Great points, I will definitely look at the solar value deflation data, thanks. Your conclusion may be mine as well, I just want to understand the tech and market well enough to be able to make a good decision when it is time to jump in.
Yeah the Tesla gear definitely gets my attention, seems like a pretty slick set-up. I’m not sure exactly what the tax rebate is currently in MA, I feel like some big ones expired in the last 1-2 years.
First thing is find out what your local power company will let you do.
There's places you can push or pull power easily; and some where they require you to buy their grade of isolation equipment before you do anything that might ever risk backfeeding a line. That's at the engineering level; the bureaucratic levels can be much worse.