Matt Potter 2:30 p.m., March 27
- Community Blog
- Encanto Gas Holder
Some Backup Benefits to Off-Grid Solar Panels
I decided to run some numbers on an always-on off-grid solar panel setup that had the least involvement of myself with the California Public Utilities Commission, the City of San Diego's solar home improvement fee, or any form of government rebate. My authority for doing this was found in FEMA's National Response Framework regarding the role of ordinary citizens and families in preparing to respond to all forms of hazardous incidents. In an all-hazard approach to comprehensive emergency management by ordinary people who can expect to be without effective state or federal responses to a catastrophic disaster for some time, we just might have an interest in having an always-on off-grid personal power solution to a sustained grid failure. It seems to make sense that no matter what goes wrong for whatever reason, we survivors will always have the need for power tools, lights, a radio and refrigeration, whether or not the local power company can keep it together every day, and especially if there is a real power shortage disaster.
Of course, having an always-on off-grid personal power source can be a good way to maintain some sort of personal economic balance, every day, when there are so many local power utility rate hike applications in the CPUC proceedings pipeline.
Right now, I am looking at a scenario where somebody decides today that sometime soon, one needs to cut back maybe fifty percent or more on what that person usually draws of the grid on a daily basis. At half power of what SDG&E has previously argued is a typical 3.3 kilowatt-consuming household, I am thinking that if somebody can generate maybe at least one kilowatt of her or his own power, then life won't be so bad when the grid goes down in a big way.
I know that there were plans for thin film solar solutions being talked about right before the Crash of 2008, and there are probably higher grade commercial solar panels out there in the market someplace, but Harbor Freight keeps sending these coupons to the house in our diminutive daily paper, typically on the weekends, and so I'd expect that if somebody was interested in doing this cheaply with off-the-self components, then that person wold start out by buying up just one square yard of solar panels at about $250, and adding in a couple of used car batteries for storage and a $30 power inverter for 120-volt output to keep at least some 15-watt CFL bulbs burning after the smart grid goes down.
There are about one million residential power customers in San Diego, with maybe half that many small businesses in the same utility service area. If everybody spent maybe just $300 on one square yard of solar panels and accessories, these customers would cut SDG&E's need to build more fossil-fueled peaker power plants by roughly 1.5 million times 45 watts, or somewhere around 60 megawatts.
By this time, I am sure that most readers are wondering about this off-grid connection that really is not a connection to the power grid. In the front yard, I have some solar powered lawn lights. Nobody paid any permit fees for anybody who wasn't a licensed contractor to stick the lawn lights into the ground. They are all solar powered, they run for free, and neither CPUC, the City of San Diego, the State of California, or the Federal Energy Regulatory Commission has to know anything about them, and their not knowing doesn't cost me one red cent. Now, if I start stringing together yards of off-grid solar panels that are not a home improvement project and then run an extension cord into the house, the same government agencies need not know about that either. If none of my own electricity that I get for free from the sun passes either way through SDG&E's smart meter, then SDG&E doesn't need to know about it as well. All SDG&E needs to know is that for the little bit of electricity that I can produce on my own, SDG&E doesn't need to worry about producing, acquiring, transmitting, distributing or metering that electricity to me or charging all of you to build more overhead lines and related power infrastructure for what SDG&E is not worried about.
At this point, we are all saving 60 megawatts of electricity that SDG&E no longer has to spend any money on. This is not bad, especially when SDG&E's PeakShift at Work/PeakShift at Home (PSW/PSH) rate hikes have yet to kick in. According to Sempra Energy attorneys for SDG&E, PSW/PSH is designed to send a price signal to small business and residential customers that daytime business hour consumption is peak rate consumption, and unless we want to be paying as much as ten times the evening hour and weekend off-peak rates, we need to shift our energy consumption to evenings and weekends or get shafted. Now, at least those of us who actually got off our assets and bought a square yard of solar panels can now run a small fan when SDG&E just might otherwise be charging us the highest peak to run that fan on the hottest days of the year.
A kilowatt-hour from SDG&E runs maybe $0.12 for a residential SDG&E power customer right now (based on somebody who showed me her bill). If we were all producing 60 megawatts of our own electricity for our own purposes for one hour, then we just saved ourselves $7200. For a day's worth of sunshine, we saved ourselves $86,400. For the month, we saved ourselves about $2.5 million. For the year starting today, we would be saving ourselves $31.1 million.
The yearly savings breaks down to only about $20 per small business and residential customer, but it does show the effect of all of us being able to generate about the smallest amount we can of our own power, without paying anything at any time in fuel costs to do so once the panels are paid for and set up. At that rate, savings equals the initial investment of $300 in about 15 years.
Over a twenty-year period, we would save $600 million on an initial investment of around $500 million for 1.5 million of us each to buy one square yard of off-grid solar panels, car batteries, extension cords, and power inverters. Our savings would have been higher, but I am lopping off about $22 million in replacement costs due to random rock throwing and other eventual panel damage. If we factor in SDG&E's proposed PSW/PSH peak and other rate hikes, our savings would be even greater.
Now, some us might like saving this way so much that we might pick up a second 45-watt square yard of solar panels and tie it in to the first off-grid panel we bought. At another $250, this purchase might happen next month or so, but over a twenty year period, if everybody who is a small business or residential SDG&E customer did this, we could be talking about a savings of close to $1.25 billion on an initial investment of significantly less than a billion for two square yards of solar panels, inverter, car batteries, and extension cords. Again, factoring in SDG&E's proposed rate hikes just saves us more by using our own electricity during the day, when SDG&E would be otherwise sending us a peak rate price signal either to shut down our lives, shift usage or get shafted.
Once SDG&E's PSW/PSH peak rate hike schedule is approved, it may be possible for people with or without their own off-grid panels to charge batteries from the grid at off-peak evening and weekend rates, then at least start the work week with some way of lowering the cost of peak rate usage from their previously-stored lower-cost power. I imagine that owners, accountants, and systems engineers at many small local businesses have already figured this one out.
Personally, I would need about 24 square yards of off-grid solar panels to generate just over a kilowatt of electricity. This ought to be more than enough to keep a 250-watt refrigerator, my various computers, their printers, lights, at least one fan, and other household appliances running no matter how many wildfires burn down the power grid across San Diego County over the next twenty years. If I start buying square yards of solar panels now and kept adding a new one every month, then I'd be generating a kilowatt of off-grid solar panel electricity from free solar fusion energy in about 2 years, while SDG&E would still have years to go in its $118 million, five years of advertising and other incentives to convince us that PSW/PSH is a good deal for us as a peak rate hike.
I can't tell anybody how much I am saving now because I am off the grid completely as a residential customer, and I don't have any SDG&E energy bill to compare anything to. All I can say is that I don't miss the local power company. When I have enough panels strung together, I'll be giving it away free to my neighbors.
A recent cost comparison by Onell Soto in the daily paper stated that the average cost per watt of home-improvement grid-tied solar panels with all fees paid and rebates applied for runs just over $7 per watt. The number came out in an article where one contractor was singled out for its per-watt rate to its customers of about $13, which the contractor probably thinks is a good deal.
Depending on whether or not Harbor Freight is running a one-per-customer sale on the one square yard of off-grid solar panels, their price per watt is anywhere from $3 to $5 per watt.
You make the call.
More like this:
- SDG&E Giving Thanks For Low Supply Leading To High Electricity Prices For Daytime Vehicle Recharging — Nov. 26, 2010
- Scoping Memo Issued in SDG&E PSW/PSW Rate Hike Proposal at CPUC — Oct. 6, 2010
- SDG&E Installing 26 Megawatts of Solar Property Improvements — Sept. 3, 2010
- City of San Diego Protests SDG&E PeakShift Rate Hike Proposal — Aug. 19, 2010
- Per Watt Savings from Off-Grid Solar Panels Balance SDG&E Proposed Rate Hikes — Aug. 18, 2010