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Any advice on solar electric?
Old 07-04-2004, 08:06 PM   #1
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Any advice on solar electric?

(I'm only asking about photovoltaic systems. We've already looked at solar water heaters.)

We're considering a home PV system. We have about 400 sq ft of south-facing roof and we use roughly 15 Kwh/day at a rate of approx 15 cents/KWh. (Hey, Oahu utilities aren't cheap but sunny days are plentiful.) The biggest appliances we have are the fridge, washer, & dishwasher. (No air conditioning.)

We think we'd want a minimum of 2 KW of PV panels but we could do more; if we cover the south roof then our livingroom will be much cooler. (I'm seeing numbers around 150W per 15 sq ft panel.) Since we'll be using HECO's net metering we've decided to simplify the system (and its voltage regulator) by not having a battery storage bank. HECO won't buy power from residential customers (yet) and we're not interested in saving money after sunset.

Does anyone else have a PV system on their home or afloat? How long have you had it? What are its specs, what brands did you buy, and how much did you spend for materials? How much are you saving (or how long is your payback)? Do you have to do any maintenance on the system or individual parts? Any problems with the PV hardware? Any voltage-spike issues with appliances or computers? Any problems during power outages? Any words of wisdom? IOW, if you were installing the system all over again tomorrow, is there anything that you'd do differently?
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Re: Any advice on solar electric?
Old 07-05-2004, 05:41 AM   #2
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Re: Any advice on solar electric?

Nords

The answer is no. But keep us posted - tweeks my interest and reminds me of my old Mother Earth News and Scientific American reading days. Camps out here (5 cents/KW) tryed some wind power in the late 70's but the mini-gusts did even the last dye hard in. Solar hot water in 'the ritzy' subdivision between here was a bust according to some of the residents I knew - cost of a/c for a big house overwhelmed everything else. The only PV around here seems to be in places it's not possible to run a wire. Or a gas gen/battery combo is not suitable.

I'm curious if PV tech has progressed in the last thirty years. We have a big south facing part of the roof but at 5 cents/kw?
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Re: Any advice on solar electric?
Old 07-05-2004, 07:52 AM   #3
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Re: Any advice on solar electric?

Hey Nords,

How do you avoid using battery storage? My concept
has always been that you store power and use a
DC motor to drive an AC generator to power your
appliances, etc. I would be interested in hearing more
details on your proposed system.

Cheers,

Charlie
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I don't think we're trying to get off the grid.
Old 07-05-2004, 10:29 AM   #4
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I don't think we're trying to get off the grid.

I've lived with submarine batteries for too many years and I think the home hazards outweigh the advantages. Maybe Dory36 or other mariners have similar stories. Submarine cells are a foot square and about four feet tall, over a hundred series-connected cells delivering approx 250-400 VDC with many thousands of amp-hours. The biggest challenge is managing the recharge cycles and freshening the electrolyte. NAVSEA was always automating the system "next year" but after 75+ years the electricians were still monitoring battery health by manually sampling the specific gravity of sulfuric acid with hygrometers. The heat thrown off by a discharging battery can be pretty impressive, too (up to 110 degrees F). I know car batteries are sealed (no SG measuring necessary) and marine batteries can probably stand a lot of abuse/neglect but I still hesitate at the idea of a garage full of hot electrified sulfuric acid in rubber boxes. Add in teenage drivers or leaky washing-machine hoses and our insurance company would probably run away screaming.

Another problem with an off-the-grid system is voltage transients. I have a lot of experience with industrial DC/AC generators, too, and again it's a maintenance/repair challenge (to say nothing of the noise). Today's home inverters are largely solid-state rectifiers from companies like Trace. They're full of high-speed integrated circuits that produce a nice clean waveform (in proportion to their cost) but they just can't support that AC voltage in the face of a transient like a refrigerator compressor or a dryer heater-- or maybe not even the kid clogging a really sucky vacuum cleaner. Running a house with both 220V and 120V appliances complicates the inverter's capacity & design (more cost). Even a good commercial computer UPS will have trouble propping up the voltage transient without eventually trashing the monitor or the HD. Compromises include clotheslines, natural-gas dryers & stoves/ovens, 120V microwave/convection ovens, and propane-powered fridges. However we don't have nat gas in the neighborhood and spouse guidance on the other lifestyle changes has been crystal clear.

So after two paragraphs of long-winded technical details, this PV system would still be connected to the grid. It's actually a strange way of thinking, since the "Backwoods Solar" catalogs show Grizzly Adams happily cavorting around an independent system hundreds of miles from any utility feeds. But staying on the grid has several advantages. HECO is required to supply the bi-directional meter (so we don't have to buy one) which means that we can have their power grid support the house voltage. Inverter voltage fluctuations wouldn't be noticed by the grid voltage in the face of the fridge's or dryer's starting transients (I really hope so) although I'm still paranoid enough to have an UPS on the computer. I don't know how the 220V-120V problem is solved but if necessary the stove & dryer could have their own separate 220V feed from the grid (although that would wipe out a noticeable portion of the savings). And what about the day I finally splurge on my personal workshop of 220V woodworking tools?

So the inverter's output would run in parallel with the grid voltage during the day and would just die out at sunset. Aside from the fridge our night-time power consumption is pretty low and all future nighttime clothes washing/drying & dishwasher activity would be forbidden under the new regime.

Lifecycle cost & payback is probably the show-stopper. A 4KW system would undoubtedly spin the meter backwards for most of the day but HECO will only "net meter"-- that means our power consumption could go to zero but, even if we drive their grid all month, they won't pay to purchase any of it. So our earnings (pending legislative change) are zero and our monthly savings would only be about $50-$60. Even at 15 cents/KWh that's a 30-year payback on a $20K system but it could be priceless after the hurricane rolls through (assuming it doesn't rip the PV panels off the trusses along with the roof). OTOH we'd survive just fine on a charcoal barbeque & canned goods, too.

Maybe my cost numbers are too high and maybe systems are much more efficient, but if I can't drag the installation down around $15K then it's probably not worth the effort. I certainly don't need more home hardware to maintain and I think my kid would draw the line at submarine-style data-logging & analysis.

But the "Cool!" factor is still pretty high... Contractors paint an unrealistically rosy picture so I depend on word of mouth from early adoptors. Unless HECO gets desperate enough to change the law and buy power from Nords Solar Electric, we're probably going to have to wait on PV for another 5-10 years.

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Re: Any advice on solar electric?
Old 07-05-2004, 10:49 AM   #5
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Re: Any advice on solar electric?

So if I get the picture, you are connecting the output
of the PV system directly to a DC to AC static inverter?

I did not mean to challenge your decision on batteries,
etc. I just did not know the above was possible.
I know a little about static inverters (1980 dated) and
I shudder to think what a large voltage spike on
your 115v line would do to the semi-conductor switches
on the inverter. Make sure the system is robust.

Cheers,

Charlie
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Re: Any advice on solar electric?
Old 07-05-2004, 10:53 AM   #6
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Re: Any advice on solar electric?

Nords

Good post. We've left for hurricanes at least ten times in the last twenty five years - a good truck/camper combo and or Visa card and Ramada Inn worked great. Come home AFTER the power is on and live in the camper while remodeling as required. After George in 98, took a couple days to slap together a stair/access to get 12 foot in the air to get in front door. Isadore in 02 was a half day job. Power failure is common in the swamp - mostly 4-8 hours, no big deal. Commercial fishermen around here have gas engine/gen rigs which are rigged to start and run automatically for bait/seafood and perhaps 'beer'? essentials.
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Batteries, inverters, & storms
Old 07-05-2004, 11:20 AM   #7
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Batteries, inverters, & storms

Chuck,

Well, taking batteries out of the picture is a non-intuitive leap. The flash of insight from the display panel almost blinded me at last month's home show. The PV output (at around 24-28V) goes into the inverter and the output is in parallel with HECO. That combined output of 125V goes into the breaker panel (although the 120v/220v issue requires further analysis).

Trace is considered to be the Cadillac of inverters. That just means that they take longer to fry, but at least their warrenty backs up their claims. Compared to one home-show vendor's German product called "Solar Boy", I think I'd stick with Trace. HECO's power quality has improved tremendously since the 1980s and I think their spikes are minimal. If I'm the guy who has to take care of it, it better be robust.

I've always had a soft spot in my heart for submarine 1970s-era 5KW static inverters; they were the only thing that saved our combat electronics during many an electrician's "maintenance" projects. Unfortunately it wouldn't fit in my seabag when I transferred to shore duty and I haven't seen them at second-hand sales!

Unclemick, I agonize over whether to stay in the house (inside the stairwell closet) during a hurricane or to evacuate to the concrete school across the road. Driving out of the storm's path is not an option here. I know a guy who stayed home during Hugo and who saved his house from the storm surge that would have flooded his ground floor. Of course the roof damage made that victory moot, but Hawaii hurricanes tend to be more messy than lethal. Besides our pet rabbit wouldn't be allowed in the shelter, so I'd hate to have to make our kid choose between me and the bunny. Spouse is a hurricane-forecasting meteorologist so no doubt I'll have plenty of detailed guidance on where I should be.

But I'm not worried about emergency/disaster power. I'm more interested in reducing our monthly utility costs, although you can see what lengths we have to go to now to realize any additional savings...

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Solar update
Old 11-04-2004, 11:19 PM   #8
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Solar update

We've taken the first step.

My spouse always reads the Sunday classifieds. 50 weeks a year it means nothing, but when she finds a "deal" then I silently groan at the knowledge of how hard we're going to work on appraising, bargaining, and getting it home. So you can imagine my pained skepticism at reading "FOR SALE: 1 KW photovoltaic system and batteries. Cost $15,000, sacrifice for $7500."

It turned out to be the proverbial car driven by the legendary little old lady. Our seller is in his 80s, recently widowed, and recovering from a broken hip. His three-year-old system was "too much hassle" to maintain so he was simplifying his life by getting rid of it.

Lest you feel that we prey on impoverished senile elderly, he proudly pointed out the four homes that he'd added to his lot (which he's owned since 1940), all of which are rented to family. His solar system was augmented by a water wheel (in a storm drain) connected to an electrical generator, and he even ran a solar water distiller next to his PV panels. He has plenty of help at his beck & call but he's too ornery & independent to do either. I looked up his tax records and his assessment is over $2.5M in Oahu's Nu'uanu Valley, where homes routinely sell for over twice their assessed value. So we felt that he was capable of negotiating on his own.

His off-the-grid system used 20 Seimens 55W panels into an ExelTech inverter with 20 6V marine deep-cycle lead-acid batteries wired in series. He'd flip a breaker to disconnect his house utility meter, flip another breaker to connect his PV system to his house, and run until the inverter alarmed on low battery voltage. His "maintenance" complaint was that it took several gallons of distilled water per week to top off his batteries. (You boat owners are probably groaning already.) Nu'uanu Valley is one of the island's worst solar locations because of its daily rainfall. He was probably only getting 2-3 good hours of sun a day and then steaming his batteries flat each night to get through Jay Leno. When I looked at them, all the cases were swollen and the plates were sulfided from excessive wear.

We hired an electrician to help us appraise the inverter & panels. It turns out that inverters are optimized for either "off-the-grid" or "grid-tie" systems and can't be interchanged. Since we want grid-tie that meant we weren't interested in the inverter (and definitely not his batteries). The panels are fine; they last for decades unless they're caked with minerals or the cover glass is cracked. I haven't purchased an ammeter yet for power tests but they deliver 20V DC at 7:30 AM.

The electrician says he usually pays $6/watt for solar panels. Our winning bid was $2000. We even learned how to install them when we spent three hours getting them off the roof and into the truck (another reason we had the winning bid).

It turns out that detailed plans & specs are all over the internet, and most of them come from the retailers. (You can still find plenty of DIYers with their own advice.) Our next step is bolting the panels to our livingroom roof (the south exposure) and stringing the wiring to our utility meter. Today's "big dog" of inverter technology is the SunnyBoy 2500 with a capacity of about 3 KW. (I have to take back all the nasty jokes I've been making about "Solar Boy" inverters. They're actually an industry leader and Trace is struggling.) SunnyBoys sell for about $2200, and we'll pay the electrician to wire all of it together with the utility meter in a 240V AC configuration that'll tap right into our existing distribution panel. (We're getting his estimate next week.) We'd learn how to do our own utility wiring except that we have to provide an electrician's license number on the net-metering contract, and I have no idea what Hawaii wiring code requires.

We expect to net at least 8 KWh per day, which will pay about $30/month. The system will pay for itself in about 17 years (which is pretty good but not exceptional). Adding another KW of panels, depending on the price, could bring the payback under 10 years. We have roof for another 2-3 KW of panels so we're still watching those classified ads...
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Re: Any advice on solar electric?
Old 11-05-2004, 05:49 AM   #9
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Re: Any advice on solar electric?

Nords, please keep us periodically updated on your experience with the solar system. I, for one, am very interested, and I suspect that others are as well. I think that a solar system might be an attractive option on a backwoods cabin (some day...).
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Re: Any advice on solar electric?
Old 11-05-2004, 10:06 AM   #10
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Re: Any advice on solar electric?

I went to a meeting where a fellow presented the PV system he installed. It had a limited battery more as a buffer than a true storage function. Here in Southern Cal the power company uses an analog meter which spins backward" when the PV system is charging into the net. No charges or rebates for specific hours of use. He paid about $4K for components and had a professional installation. Not counting his personal time he figured out it was an 18 year payback under current pricing systems.

My sister had a unit installed in her Arizona home. She cannot send power to the net and does not have a battery and the best she can hope for is a 20+ year payback.

My conclusion after discussions with these and several other people that installed such systems is that there is no compelling financial reason to go to PV systems. It may yet come to that, like when we get oil from tar sands because crude goes over $50 a barrel. And LNG may be a good investment and then maybe PV systems. There may yet be a payback but not under current forecasts. Now if the cost of components and installations goes down or PV efficiency goes up then I'll be in the next group to do an installation.
I am interested in your experiences; everyone else I know is situated in more desert conditions. Do keep us informed.
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Re: Any advice on solar electric?
Old 11-05-2004, 12:01 PM   #11
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Re: Any advice on solar electric?

Quote:
Here in Southern Cal the power company uses an analog meter which "spins backward" when the PV system is charging into the net. No charges or rebates for specific hours of use. He paid about $4K for components and had a professional installation. Not counting his personal time he figured out it was an 18 year payback under current pricing systems.

My sister had a unit installed in her Arizona home. She cannot *send power to the net and does not have a battery and the best she can hope for is a 20+ year payback.
And he hasn't even gone through a roof replacement yet. Usually the roofers say "Uh, you'll have to remove that crap before we'll go up there..."

I'm not an electrical engineer, but I think that any analog meter will spin backwards. Utilities that don't offer net metering either aren't aware of its benefits or don't care. Consumer activism is necessary on both fronts to get the utility to start up the program.

Our local utility is getting ready to replace our analog meters with digital models that will offer time-of-day metering (most expensive rates will be between 5-9 PM) and remote shutoff. If you volunteer for the RS program, the utility can shed your load at their discretion to avoid brownouts. You specify what they can kill-- for example, your water heater but not your fridge-- and they pay you a monthly retainer. I think we'll be offered $3/month for the water heater switch.

Net metering has some "gotchas". Our utility has a $16 "minimum monthly charge" unless you have them disconnect your service. (But we don't want to go off the grid.) HECO also won't buy back any more than you use-- your meter can spin backwards 24/7 as far as they care but your net usage can't go negative at the end of the month. (And at the end of the month it's reset to zero again.) Their justification is that they're crediting your net use at the residential rate but they'll only buy power at the (much lower) wholesale rate-- and they have no plans to do so. When analog meters are replaced with digital, variable-rate metering will be much easier to implement and they'll probably consider buying more power from us forward-looking homeowners.

Quote:
My conclusion after discussions with these and several other people that installed such systems is that there is no compelling financial reason to go to PV systems. It may yet come to that, like when we get oil from tar sands because crude goes over $50 a barrel. And LNG may be a good investment and then maybe PV systems. There may yet be a payback but not under current forecasts. Now if the cost of components and installations goes down or PV efficiency goes up then I'll be in the next group to do an installation.
I agree that it's not compelling-- yet. But my "PV Payback" spreadsheet got a lot more interesting when I added in this year's 10% jump in fuel costs (Hawaii imports all our oil) and annual 3% increases (very conservative for a payback calculation). If we have an oil-shipping crisis or another Hurricane Iniki then I'll have to buy a shotgun too.

Our biggest epiphany was technology. I did a huge amount of research 10 years ago, joined the fan club, but gave up at the disappointing progress. The home show and that classified ad brought me back to the research and it's much better this time. Panels are getting marginally more efficient every year and I think the inverter-reliability problem has finally been solved. Add in a couple hours of roof repairs on a sunny day and we realized that we could cram 5 KW on our rooftops if we pushed hard. But that's only if HECO changes our net metering to a purchase program.
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Re: Any advice on solar electric?
Old 11-06-2004, 06:22 AM   #12
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Re: Any advice on solar electric?

I haven't done any financial analysis of the payback period for solar energy at home, but my understanding is that such systems are overhyped as environmentally friendly when that is really not the case. Two factors:

1) It takes an enormous amount of energy to create PV cells...I have seen estimates that it can take up to 50% of a PV cell's lifetime ouput just to manufacture one, and that energy is probably coming from an old-school fossil fuel power plant.
2) The industrial processes used to create PV cells involve a lot of caustic chemicals and produce byproducts that have to be disposed of somewhere.

Similar to problems with the electric cars...electric cars still need to get their energy from somewhere (probably a fossil fuel utility plant plus you have to deal with the inefficiencies of power grid distribution). Not to mention their batteries have lots of heavy metals that have to be disposed of once they wear out. Whether this is a better option to the internal combustion engine, I don't know, but it's not as obvious a decision as some make it out to be - "I'm driving an electric car, so it MUST be good for the environment."

Not trying to influence your decision, just throwing some more ideas on the fire. Maybe with more PV early adopters such as yourself, these problems will start to be corrected through improvements in manufacturing technologies.
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Re: Any advice on solar electric?
Old 11-06-2004, 12:09 PM   #13
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Re: Any advice on solar electric?

At least he got some that already existed, and paid pennies on the dollar for them.

I suppose in general it might not be a good investment if you're buying new panels and paying full price.

Hell, with the amount of sun I get around here, and an electric bill that starts at $80 a month when I'm not heating or cooling, I'd consider it.
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Solar insolation maps
Old 11-06-2004, 10:36 PM   #14
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Solar insolation maps

Hey, TH, according to these you're at least as sun-drenched as we are...

http://www.homepower.com/education/solar_map.cfm

http://www.eere.energy.gov/state_ene...r.cfm?state=CA

http://www.state.hi.us/dbedt/ert/solar-maps.html#oahu

and you're paying a lot more than 15 cents a kilowatt, too.
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Re: Any advice on solar electric?
Old 11-07-2004, 08:52 AM   #15
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Re: Any advice on solar electric?

Yep, looks like we're in that 6000 range, and electricity IS expensive here.

Wasnt too bad before I got married when I technically qualified for "low income" electric rates because I had no earned income.

That was a funny telephone call when I told them I didnt qualify anymore. They told me that NOBODY had ever called to take themselves off the low cost program anymore. They screened a few thousand people at random every year, almost all of which mysteriously "just" started making enough money to no longer qualify, but that was about it.

I have a couple of great places to mount solar too...besides on the roof, I have a couple of open space area that would be perfect. In fact, I have a non-used clothesline that gets sun all day...pair of metal "T"'s set in concrete over a deck...I could cover the deck and mount something on top of the covering.

I dont think I'd be interested in batteries and all that stuff, but if I could spin the meter backwards and I could find an inexpensive used rig that doesnt require Spock to set up and maintain, I might fiddle with it.
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Solar update
Old 04-03-2005, 07:12 PM   #16
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Solar update

The solar contractor agreed that we could do the mechanical part (where his special tools & training make most of his profits) if he could finish the electrical during the slow season. The house's livingroom roof faces south (quite hot in summer) so we bolted the panels through the roof to the room's cathedral-ceiling beams (surprisingly without making any new "skylights"). With labor skills straight out of "Family Handiman" magazine, we now have some roof shade with at least 10 hours/day of south sun on the panels.

We learned a lot of electrical code, mostly by redoing our "common sense shortcuts". I got heartily tired of dragging multiple strands of 10-ga wire & an 8-ga solid ground wire through 100 feet of conduit in 100-degree attics and of driving 45 minutes to buy $2 stainless-steel lay-in grounding lugs. But last month the contractor finished the electrical hookup for $75/hour & parts.

The panels (in series) generate 400VDC open-circuit. Most of the power is produced at ~350VDC and ~3A which our Xantrex 3G inverter converts to 240 VAC tied directly to the utility grid (no batteries). The grid handles power surges (like refrigerator startups) so there's no voltage fluctuation in the house. The tradeoff for this (cheap) simplicity is that the inverter only works when the grid is up. The system is absolutely silent and, except for bird droppings, maintenance-free.

Here's what we've spent so far, including mistakes & paperwork:
$112.50 Electrician's consult on PV panels
$2,000.00 20x Siemens 55w panels (1.1 KW)
$76.89 U-Haul truck for PV panels
$21.37 U-Haul gas
$101.39 PVC conduit, wire, fittings, wirenuts
$31.48 More PVC conduit, wire, fittings
$122.92 8-ga ground wire, 10-ga THHN wire
$29.48 Grounding straps, screws
-$14.73 Return half of grounding straps, screws
$15.43 Copper split bolts (for ground wires)
$10.15 PVC junction boxes
$19.96 Ground lugs, screws
-$16.47 Return ground lugs
$36.40 Stainless lay-in ground lugs
$38.54 10-ga XLP exterior connecting wire
$4.98 Stainless ground screws
$2,865.91 Xantrex inverter & materials
$750.00 Electrician labor
-$82.69 Return split bolts, PVC, wirenuts
$561.00 Permit fees ($411 govt + $150 runner)
-$708.00 2004's 35% HI renewable energy tax credit

$5976.51 Total

A complete PV system in Hawaii retails at ~$10K/KW (after tax credits). Since our state taxes are pretty low, it'll take us two years to use up another $1500 of credits and bring the net cost down to ~$4500.

Entertainment value of watching the meter spin backwards-- priceless.

Our electric bills were $85-$90/month at ~15 cents/KWhr. We've been averaging 4 KWhr on "winter" days but that's climbing as summer approaches so we conservatively estimate $300/year savings. (That's a 15-year payback without adding additional capacity, or the equivalent of a 6.7% dividend.) HECO's net-metering agreement reimburses our consumption at the retail rate, so our bill can go to zero but we can't make more money by selling the excess power. Until Hawaii's legislature changes the law there's no incentive to make more power than we use.

In the next couple years we'll add another 1.5-2 KW from eBay, classified ads, or retailer's closeouts. World demand has spurred production so PV panel prices are dropping as scale & efficiency improves. Now we know how to mount & connect the panels without contractor help, so if we triple capacity for under $4000 then our payback drops to 5-6 years.

A more complex accounting compares our savings to investing the expenses at 6% annual return. The payback is longer but the numbers are more realistic (salesmen don't use this method!). If electrical rates rise (oil produces most of Hawaii's electricity) then the payback accelerates even more dramatically.

Still debating if I want to plug the inverter's RJ-45 port into our PC and monitor real-time production... but I'm way behind on surfing.
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Re: Any advice on solar electric?
Old 04-03-2005, 09:03 PM   #17
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Re: Any advice on solar electric?

If you do run the bill to zero, could you jumper your setup to a neighbors 'grid' and drive his meter backwards as well for a small fee, such as a case of beer every week?
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No problem!
Old 04-03-2005, 09:11 PM   #18
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No problem!

With what I've learned, absolutely. I even know how to make it code-compliant!

Our neighborhood homes have a 100A utility feed with a spare 20A convenience breaker on the same buswork. It's almost too easy.

We live next to a lot with a large water-utility building on it-- the flat roof must be 1000 sq ft. If HECO ever starts paying for power (probably more like 4 cents/KWhr than 15) then I'd be mighty tempted to sneak a 10 KW rig onto its roof and run the wires over to our lot. One mishap with a backhoe, though...
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Re: No problem!
Old 04-04-2005, 07:01 AM   #19
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Re: No problem!

Quote:
We live next to a lot with a large water-utility building on it-- the flat roof must be 1000 sq ft. *If HECO ever starts paying for power (probably more like 4 cents/KWhr than 15) then I'd be mighty tempted to sneak a 10 KW rig onto its roof and run the wires over to our lot. *One mishap with a backhoe, though...
And for that, my friend, you should receive the Ultimate Guerilla Solar t-shirt from Home Power magazine.
http://www.homepower.com/magazine/guerrilla.cfm

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The revolution lives!
Old 04-04-2005, 07:55 AM   #20
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The revolution lives!

Thanks, Judy! I guess a real guerrilla would wait for the system to pay itself off before squandering the profits on t-shirts. But I don't think Dilbert would be able to wait either.

We've re-examined solar water heating and realized that what HECO doesn't know won't hurt us. Even after state tax credits & HECO rebates, a professionally-installed system costs $1500-$3000. We've found a couple used panels and we'll try to do it for under $500. No rebate, but I won't have to comply with their over-engineered requirements.

OTOH I've learned to dread the days when my spouse reads the classifieds...
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