So is hiring a contractor to build a website. Do you still feel that's "unreasonable" ?
Hiring a competent developer to build a simple brochure website shouldn't cost as much as a small car, but yet here we are.
There's zero reason to write any code by hand for a brochure website.
When it breaks I expect to replace it with a 10kW system tied to Powerwalls which avoids the rate plan shennanigans by not having to deal with ANY rate plan.
Do you mean during peak ok hours you’ll operate off battery power?
I’ve read something about PGE charging customers for using solar - arguing that solar customer aren’t paying into the system for keeping up the grid. Are you referring to that scenario and do the batteries help with that in any way?
In terms of maintenance this is a really simple setup since there are no batteries to maintain. The inverters do not require periodic maintenance and the panels only need to be washed off periodically to keep them operating at their peak. In the time we've been operating like this we lost one inverter and one panel which was damaged from a falling rock. So easy to maintain, and trouble free.
The question then was "how much does the power company pay for power that you produce?" The terms and conditions of what you pay, and what the power company pays, is nominally the "rate plan."
When we started, this was new to PG&E and we were on a plan where we stopped getting monthly bills, instead the mechanical meter would run forward when we were drawing power and backward when we were generating power. Each month we'd have a 'net power' which could be positive (used more than produced) or negative (produced more than used)and every 12 months that was summed up. If the number was negative they would just zero it out and roll over to the next year (free power for them), if it was positive they would charge a stepped rate based on total power used for the year. Once they got "smart" meters installed they got creative with the plans, we ended up on a plan where they pay us a wholesale rate, bill us at a retail rate, and total $ up instead of actual power used. This works out better for them and extended the time it took for the system to pay for itself.
Powerwalls can (and in our case will) completely disconnect you from the electric grid. They don't buy any of your power and you don't buy any of their power, hence no rate plan. If you size the system you can be pretty sure you won't ever be without power (even with a series of cloudy days) and you can add a natural gas fueled electric generator[1] (we would still have gas service) which could charge the powerwalls in a pinch.
I've got all the feeds instrumented so I can tell exactly how much power the house is using and the panels have generated (fed into an influxDB time series database) and using that data have been planning for the retrofit based on our usage over the last 15 years.
The Powerwalls double the initial installation cost but since I'm not paying margin (selling wholesale and buying retail)to PG&E the actual value delivered is higher and so it has a better rate of return. Of course I can only speculate on the lifetime ownership costs of Powerwalls (much like I had to do with the inverters which I had in my spreadsheet being replaced every 10 years since that was the warranty on them).
[1] What I really wanted was some Bloom Energy fuel cells for that but they don't really have a 15 - 20kW rated one, it is too small.
PG&E still plays rate-plan shenanigans. Besides the retail/wholesale stuff, they charge $10/month just for the grid connection. They're currently lobbying CPUC to raise that to $60/month.
Also the "time-of-use optimized" setting in the Tesla app isn't actually that optimized. It's unaware of the retail/wholesale issue, and hence simply tries to maximize the amount you ship back to the grid in peak hours when it'd be better off minimizing total consumption. It also sometimes doesn't discharge the PowerWall as much as it could (leaving solar energy on the table), and it charges it with grid power when it could easily use solar energy. I've found it's better to just use the "Self-powered" setting, where it charges the PowerWall as soon as you have excess energy over the home consumption, starts discharging as soon as there's a shortfall, and continues until the PowerWall reaches the reserve level you set.
Note that solar generation is incredibly seasonal. I'm currently generating about 25 kWh/day. In January, this is more like 4 kWh/day. So depending on your shade levels, you might have to put on 6x as many panels to be entirely grid-independent vs. grid-connected with battery backup. We're sized so that we can power a full normal workload from about Apr - Oct, which at least covers fire season, but would have to conserve significantly (i.e. forego loads of laundry and electric appliances) if we had an extended outage in winter.
In the summer, the sun is higher in the sky, so it clears the hill earlier (by 8 AM or so) and never hits the trees. Both arrays produce the full day, and the days are longer, and the sun is incident at a steeper angle anyway.
My situation is a little weird, but it also applies to many urban or rural settings where you'd have a tall building or series of tall trees that block sunlight when the sun is low on the horizon, but that the sun would clear when directly overhead.
On the plus side, you can put them in a subterranean vault if you have space on the property for the set back limits.
In summer I generate 40kWh a day, winter down to ~23kWh (AU is lucky though in this regard), which nearly always exceeds my home usage. 20kW of panels is huge, at least 60+ panels + I'm guessing multiple large inverters or lots of micro inverters.
$1/watt installed is really cheap IMO at this scale residential.
https://news.energysage.com/how-much-does-the-average-solar-...
Also rooftop solar is 2-3x the cost of utility scale solar.
The opportunity cost of that $10,000 is, let’s say 5% per year on avg, or $2500 over 5 years (without compounding which would skew this even further against panels)
With your electric utility, after all the additional fees, you’re probably at at least 15c/kWh.
Storage simply needs to cost less than 13c/kWh to make economic sense.
For 25 years, at 20% capacity factor, that will generate 96kWh a day, for a total of 876MWh. That's 2.3 c/kWh, not accounting for the time value of money. Call it 4c or 5c/kWh, if you take out a loan rather than paying up front. I dont know of any utility thag charges that little for electricity.
Of course, 96kWh/day is pretty high on the curve of household energy consumption, so most US customers wont get your economy of scale.
(Assuming one even bothers to use the car as an in-betwee).
I just bought 5kW of used solar panels for $1k shipped to my door. You can get new panels for around double that ($0.27/watt). My 3kW inverter + charge controller (can run w/o battery) was $750.
The inverter powers a critical loads panel, which switches to grid when solar isn't available. I setup the panel, I had an electrician move my critical loads and connect my inverter.
That said, this is not the standard grid-tie setup, but it works for me. The advantage for me is price and the ability to add a battery later.
But 80% is still rather decent for home use especially if you have space for more of them. Buy dirt cheap, use for another 10-20 years.
(I don't mean to deter you, I dropped 20k on home solar, but it wasn't really for the economics).
https://www.pv-magazine.com/2021/07/02/exploring-the-depths-...
Industrial installs are encouraged by utilities because they increase dependence on expensive, centralized, infrastructure. And for regulated utilities, this sort of infrastructure expense is easy to rate-base and increase profits.
But independent modelers that have been looking at fine-grained grid modeling, like Christopher Clack, have found huge cost savings by deploying massive amounts of storage and solar at residential and C&I locations first in the coming years, before doing larger industrial scar installations.
Ofc, local storage is an option, but will it be cheaper and safer than what we currently have? 20-30+ year old battery installations left to operate and just hang there don't look too promising to me...
In nearly every market, energy use peaks at mid-day, just as solar is peaking. So distributed solar is a peak-shaving system, whereas centralized utility solar still requires the same big peak.
Distributed storage reduces both troughs and peaks, and makes T&D even more efficient.
PS: it's also a harder system to attack for malicious operators.
https://en.wikipedia.org/wiki/Electric_power_transmission#Lo...
How's that?
https://cecgis-caenergy.opendata.arcgis.com/apps/california-...
You'll see that on the scale of substations, industry is right next to residential, and virtually indistinguishable.
Consider 500MW placed on the roofs of homes in San Jose, versus 500MW in a somewhat close green field build. The distant green field build is going to send every single kWh over transmission lines. Where as close to 0 kWh of the residential solar would hit transmission, meaning that all transmission requirements are lessened, as are distribution requirements.
The opposite: the closer you place production and consumption the better. Less energy wasted in transportation, less costs for infrastructure maintenance, less risk of widespread outages.
However, decentralizing access to solar energy goes against the interest of energy companies, the gas industry, the nuclear industry and, consequently, the political class.
Not sure about that. In general it's centralization that reduces maintenance costs. Centralizing in terms of location lets you use bigger, more efficient hardware, and gives you economies of scale. Centralizing ownership reduces administrative costs and allows for savings not possible with distributed ownership.
I do see the various benefits of everyone running their own energy production, but costs and reliability aren't them.
The efficiency of solar panels stays the same with the number of panels deployed next to each other.
The infrastructure to transport electricity (pylons, cabling, transformers) becomes more expensive with increasing capacity. Less centralization requires less transport.
15kW will produce ~450MWh in 20 years (1500 hours of sun per year, varies between countries).
20k$/450MWh is 4cts/kWh which is pretty good IMHO
https://www.ikea.com/be/fr/customer-service/product-support/...
The prices include taxes & installation, and it's probably not the best deal.
That's $1462 per kW. Which is pretty much what I see in the US.
Unfortunately thats where the real action is, as much as i'd love to replace all energy generation with 'people's solar' its unlikely
My residential solar will be ridiculously expensive, probably close to $20K.