Solar Power Stations

[Texas Proud]

IMO... I would want to be connected AND have batteries if possible...

I would want the batteries in case of power outages and power 'blips'... we get them on a semi-regular basis here and it gets me pissed.... I bought UPS systems to back up my computer and TV / VCR since it happened so much...

BUT, like others, I have a high load with air 9 months of the year and of those 3 are very high...

So, that is why I said $5K... because I think it would cost close to $25K to do my house... living in Hawaii has a big benefit in weather...

BTW, there are some 'new' roll out PV cells that lay flat on a roof... you could use these for the street facing part of your roof....

 

[Brat]

Under research is a paint type application too.

Once PV installs become cos-effective I think many will opt for that solution. It is cost effective for Nord now because he has the skills, others will need to wait a while. The inertia isn't the technology, it is the cost.

 

[TromboneAl]

I'm sure a grid-tie system wouldn't work for us. We use less than 10 KWH per day, most of the sun hits the surrounding trees, and we have a lot of fog.

I know very little about solar panels, etc, but I wonder about something like this: what if you had some solar panels hooked up to some non-essential DC devices that you only needed during the day. For example, small space heater, ceiling fan, ambient lighting. No batteries, no power-using inverter, no monthly fee to electric company, just solar panels and two wires that bring 12 VDC down into the house.

So, let's say that in our house, the sun comes up, and during the day we have solar panels running a 500 Watt DC space heater. Enough to keep a small room warm.

The idea is that by eliminating all the complicated stuff, you might get some benefit out of a very simple system. Ever heard of something like that?

 

[Telly]

The Solar Power Station I want is the big satellite PV array in space at the geosychronous point. With the power beamed back to earth via microwave, like the concept of the late 70's. But I want full control of aiming and focusing the beam

 

[Nords]

Never mind. I found books that appear to answer all the questions I had plus more.

No problem, sometimes doing nothing is my best tactic. (Well, OK, our kid was hogging the computer last night with lame homework excuses.) Let me know if your analysis runs into roadblocks-- I used Keith Cronin's website as one resource and I can point you to HECO's Ron Richmond and a local engineering thesis student named Jeff Mikulina. All nice guys.

Where do you find cheap panels, though? A quick google found me a 161.5 watt panel for $850. That's new, of course, but it makes the system really expensive. I did a quick calculation and it looks like it would take a 28 panel system to meet my energy needs at 5.4 peak sun hours, 80% battery efficiency (I think I could take that factor out if I did a grid-tie system like you), and 90% inverter efficiency, assuming 16.86 kWh / day usage. That system is $24K just for the panels, which is obviously way too high.
I think unless I find cheaper panels or move to a sunnier area this may be a non-starter.

It's not impossible but it takes a lot of time & patience. We bought old used panels-- parent or even grandparent technology-- and blemished factory seconds. They all have lower power density & conversion efficiency so they "waste" a lot of roof space. You pay a premium for higher densities & efficiencies but a 3KW system can indeed cost close to $30K.

Unfortunately $5.25/watt is a pretty good retail price. Your rough $24K for 4500 watts of panels isn't too far off considering a $3K inverter plus mounts, racks, connectors, & labor. Many modern panel designs cost $6-7/watt retail and up to $9/watt installed.

Keep in mind that we spent a grand total of $14,500 on our current 3 KW system and I haven't yet installed another five panels that cost $1075. We've already racked up $6000 of tax credits over the last three years' returns and we have another $1700 in the buffer. Those subsidies really make the $$ math work.

The mechanics of finding cheap panels comes under the heading of "Whaddya do all day." My last buy was on eBay. It was his first sale (under that name, anyway) so no one else was bidding. He even paid for Hawaii shipping so my cost came to about $3.36/watt. I ran a daily search for over two months, sorted through hundreds of items each day, swapped dozens of e-mails with sellers, and dropped out whenever the auction bids exceeded $4/watt. The other business retailers who sell panels on eBay generally agreed that I was a cheapskate and refused to discuss less than $5/watt. The best deals come from estate sales, storage auctions, and other one-time sellers who really had no interest in what they were getting rid of.

My next largest purchase was from Sun Electronics in Miami. They sell heavily on eBay and I bought $7000 of cosmetically-blemished Evergreen 115-watt panels from them. That was a bit of a leap of faith (as well as the $700 shipping fee across five time zones that took a month) but they gave good service and the panels make up most of our array.

Interesting. What I had read so far this afternoon indicated that a grid-tie system is complicated by the fact that the power company will want to inspect your system and impose requirements on it so it doesn't foul their power system up. I can see how skipping the whole battery part of the system would make it simpler from a design point of view.

Yep. Grid-tie is the most cost-effective design but it involves a lot of people whom you'd rather not deal with. Not only do they want to inspect it, but you'll need a construction permit and a licensed electrician. Keith was extremely patient with me (I kept trying to apply logic to the building & electrical codes) and he did only the electrical work yet I was thrilled to pay him over $400 to run the permit paperwork. Jeff Mikulina told me that out of over one million Oahu HECO customers, we're one of only two dozen homes with grid-tie PV permits. The city's permit staff and HECO's "inspector" had never seen a PV system before (literally!) but they were happy to approve the paperwork that Keith had previously run through HECO and the local legislature. I'm not implying that Keith had bribed anyone-- his contractor's lobbying group went through a tremendous education effort to smooth the bureaucratic approval process. After I'd tried it on my own I would have paid him $800.

A couple months after we'd installed our system, including the permit inspection and HECO's approval of the net-metering contract, a separate branch of HECO sent an inspector out to the house. His job was monitoring their accounts for abrupt changes in customer energy useage-- we'd popped up on their list as either possible energy thieves or missing/dead. He'd also never seen a PV system before and Ron Goodman took a lot of teasing from the contractors about that one.

Google "guerilla solar" for stories of homeowners who just don't want to bother the utilities or the regulating agencies...

I don't really care about going off grid except for the cool/geeky factor of it. I am interested if I can invest capital up front that provides me with a return that speeds up my FIRE date.

There are three ways to look at it: return of capital, dividend, and opportunity cost.

The fastest payback, most favored by contractor sales staffs, is the return of your capital. It's the cost of the system divided by your monthly savings, and a "typical" ROC is 20 years. Tax credits (and excavating the bottom of the barrel) reduces that to 10-15 years, and rising utility costs (the energy CPI?) may reduce that by a few more years. It's highly variable and location-dependent so you end up doing your own research & calculations.

The second-fastest payback, also popular with sales staffs, is dividends-- especially since you don't have to depend on the stock market or a bunch of company execs. But although the dividend rate may be among the market's highest, paying back a 7% dividend still takes over 14 years.

The most accurate method is opportunity cost. (You'll never hear about this from a sales guy.) I assumed that every penny we spent on a PV system could've been invested in a low-cost index ETF returning 6%/year after taxes. I model this with a rudimentary spreadsheet to track its growth against the growth of our PV savings. Every month I read our KWhr production, check HECO's $/KWHr retail rate, and compound that amount at 6% APY. Even with the tax breaks the two lines don't cross for another 11 years. I didn't measure the energy savings of our solar water heater but I suspect that it's a big part of the overall picture-- yet that's a reduction in consumption.

Unfortunately for my my south facing roof is the right side of my garage roof, which faces the street. I think my HOA folks would have an issue with solar panels. Maybe not.

Luckily ours faces the sewage booster station at the end of our cul-de-sac and our system is not easily seen from the street. Our HOA had no objections but you're right, it'll probably require their approval. The good news is that they won't want to look like green Luddites and they'll probably approve the panels just to stay out of the media.

CFB has correctly pointed out that no homebuyer will pay for your PV array. I wanted to look at a local guy's system and found that he'd moved to the Mainland, but he gave us the phone number of the new owner. The new guy graciously showed us around but had no idea what the PV components did, where they were located, or how they affected his electric bill. He admitted that if they broke then he wouldn't even bother trying to get it fixed.

The flexible rollout panels fill me with Dilbert engineering consumer lust; they're going into a local military base-housing neighborhood to become the nation's largest residential solar installation. Ovonic also makes a line of PV roof tiles that looks incredibly cool. In two or three decades our new south roof will probably use those... unless I see them on eBay sooner!

T-Al, I've seen small systems like that at Home Depot. They were advertised as "laptop power supplies" or something similar-- just a panel, a black-box inverter, and a receptacle plug. One of my favorite references for those products is http://www.backwoodssolar.com/

 

[SecondCor521]

Thanks for the detailed reply.

My analysis at the current time says it's not feasible for me, for the following reasons:

1. Unlike Hawaii, my state offers only a deduction of the costs, not a credit. And this deduction is spread out over four tax years.
2. My cost per kWh is really low.
3. I don't get enough peak sun hours where I live to generate enough energy from the PV cells.
4. It looks like the federal energy tax credit for solar systems expires at the end of this year, so I only have one year of federal credits available.

The PV panels themselves would be about 381 square feet, which I would assume you'd have to increase by a few percent to account for the roof mounting hardware. Given that the ground floor of my house is approximately 1500 square feet, and that the slope of my roof provides additional surface area, it does look like the system would fit on my roof.

The current cost of the PV cells in my spreadsheet is down to about $17K after finding a cheaper retail source and eliminating the battery pack. But that total doesn't include the regulator, inverter, grid-tie stuff, and any regulatory stuff such as permits, electricians, and electricity company inspections. Even with just the PV cell cost the analysis doesn't make sense.

Buying used and seconds panels is what I suspected you were doing. I don't know if I have the confidence or knowledge to do that. I don't think I'd do guerrilla solar for the same reasons.

Another good thing, though, is that learning a bit about this stuff has prompted me to take a look at my electric consumption. Just making the list of every electricity-consuming device in my house was eye-opening. I assume that I'll be able to evaluate and trim my costs just based on that. Then perhaps a smaller system, spread out over a couple of years (if the federal government extends the credit) might make more sense, because the credits -- as you well know -- have a $2,000 per year cap on them.

2Cor521

 

[ERD50]

I know very little about solar panels, etc, but I wonder about something like this: what if you had some solar panels hooked up to some non-essential DC devices that you only needed during the day. For example, small space heater, ceiling fan, ambient lighting. No batteries, no power-using inverter, no monthly fee to electric company, just solar panels and two wires that bring 12 VDC down into the house.
.....
The idea is that by eliminating all the complicated stuff, you might get some benefit out of a very simple system. Ever heard of something like that?

It could make a lot of sense. Low expectations, low cost, keep-it-simple approach. I don't think you could get rid of both batteries and the inverter though. Things like 12VDC lights or a 12VDC ceiling fan want a fairly well regulated power, the panel's output will be all over the place over the course of a day, or as you turn different loads on/off. The heater could work, but there are cheaper ways to heat than with electricity (but not cleaner than solar).

In addition to Nord's link, you might check out RV type applications. Loosechickens was describing their RV system a while back.

I think the key to payback is still going to be using all the energy that the panel produces. You are going to need batteries to match up your usage to your production, or tie to the grid to use it as the storage system. Else, the panels are producing juice when you don't need it, and you want to use it when they aren't producing enough. The panels themselves are just too expensive to put them in a 'use it once in a while' mode and get a payback, I would think.

-ERD50

 

[winnie]

Yeah its possible. I was just pushing Nords' buttons on the solar power.

Realtors i've spoken with about this have been pretty consistent. You have to find the right buyer, someone who 'gets' the whole solar power thing. Otherwise they're attracted by the savings but concerned about the unknown technology and any maintenance it might require. Either way, most agree that it doesnt add a lot of value to the house.

One said its a lot like an inground pool. Some will like it, some wont, it might tip a sale in your favor vs a property that doesnt have it, but you arent getting 40k extra on the sale for a pool you spent 40k on.

We bought our house in N. CA last year with a solar, grid-tied system that cost the original owners 20k to install (it was a then state-of-the-art system where the solar panels look like thin black vinyl tiles, not the big bulky panel-type).

We were the kind of buyers who didn't "get" the idea of solar and were worried about upkeep of the unknown technology. But we loved the house, and bought despite, not b/c of the system.

Two years later, our yearly electric bills are about $200 on a 2300 square foot house and we really love having the system. It also forces you to pay attention to *all* your electric usage, which is really a good thing.

Nothing like the zeal of a convert, but now we think it should be mandatory that builders install these systems on houses when building in places like S. california, Nevada, etc etc.

winnie

 

[ERD50]

So it sounds like the quickest way to get payback on a solar installation is to buy a house that already has it! If it does not raise the value of the house much at all, you are getting it at a deep discount, and didn't have to climb on the roof and scrounge around for used panels like Nords

Actually I'm a little surprised it does not raise the value more (but not surprised it doesn't raise it the full amount - that is a long payback for most systems). They seem to be very maintenance free, and should last the 30 years or more. I would be a bit more hesitant about solar hot water - pumps, complexity, freeze issues in this climate, potential for leaks, etc, etc.

I guess solar photo voltaic panels will just need to become more mainstream before a decent value is assigned to them in the used housing market.

-ERD50