cost of PV

I don't think finding land is the issue. How many shopping mall, industrial building are out there just soaking up heat? I am also not sure that utility scale is the real answer. I think that there is some merit in a disagregated system of PV scattered through out the grid.

Another example, what is the matter with putting small arrays (1 kw?) on millios of utility poles through out the distribution grid? You have dozens of poles per mile, if each were tossing a few kwh into the grid it would have no impact on the local environment, use no land, and would have a significant effect. Granted you have issues with higher voltage transmission lines and inverter capacity, but this can be over come with inverter design. Even if you put an array on ony. He poles that have a line voltage transformer, that still is tons of poles!

Just some thoughts.

Icarus

 

even in cloudy WA, solar has generated a lot of interest, but its a bad economic time. even with a payback of 5-7 years (WA has very subsidized solar buy back program) people are still hesitant to go into deeper debt.

but one thing that has really caught on is solar leasing where the owner provides the roof space and gets slightly reduced electrical rates and the installer gets the big payback from the ultilities

 

The problem is the up front cost. People don't buy more expensive appliances often if they have to pay more up front, even if they realize that they will save energy/money over the life of the appliance. I would be fine with a seven year pay off, but I don't plan on moving. Many people don't stay in thier houses that long, and I don't think that a PV system will add to the market value of the house as much as it's cost. (even though it should). I get no credit on my loan appraisal for solar hot water, and passive solar het, even though the house is cheaper to run.


At scale with the engineering done, how much real installation time is involved in a simple small array on a power pole? Uniform components, it would seem a couple of linemen could do it in less than a day, much easier than doing on off residential or small commercial installs that require individual design and wiring issues.

Icarus

 

That's a heck of a price. almost 4 years ago, it was $40k here installed for 5.2 kwh. 50% covered via rebates and tax credits, and an SREC market that's tanked to be almost not worthwhile.

I think the rebates now are 35%, so you can still get a system significantly cheaper than I did 4 years ago.

FWIW, I average 6000 kwh annually so far here. If this weather continues here, it'll be closer to 6800 kwh this year.

In PA, there are solar panels on a lot of the old wooden utility poles. I thought it was a brilliant usage of them. Just think all the traffic lights, etc that could have a single panel on them. You'd think the power company would do it, to cut their long-term costs....oh wait, corporations in the USA don't think long term, my mistake

 

I start with assumptions about average lifetime output: PVwatts annual * 25 years. Panels are probably good for 30 years if good quality, but lose about 1% a year production.
I then add $1/watt for possible (likely ?) inverter replacement
Last assumption, financing costs will about even out with retail electricity price increases over time. This lets us ignore time value of money.

Example:
4 kw array in my locale by PVwatts will produce ~ 7800 kwh/year (from memory)
Over 25 years production is 7800*25 = 195000 kwh
If before subsidy installed cost is $8/watt, and 40% subsidy is available, then
installed cost + inverter replacement cost = $5.8/watt * 4 kw

soooo cost/kwh is 11.9 cents.
If SRECs are involved the calc is a fair bit more calculated; and if the SREC is variable and unknown then just make your best guess. You would also have to know if the SREC is transferable when the house is sold.

Yes, local costs are $8/watt. The installers are aware of the tax breaks, too.
It is FAR from clear how much non-depreciated installation cost is returned when the home is sold. This is the major rational reason people are hesitant to buy clean tech. I'll also point out that one negative side-effect of letting China take over PV panel production is that the actual warranty on the panels is ... uncertain. I'd say zero to be safe; time will tell what quality people actually buy in the race to the bottom for panel prices. You can somewhat hedge your bets by having the installer warrant the panels, but you will pay more (quite a bit more), while installers come and go, or change their names but do not remember their past warranties under the old name.

 

I'm not upset that the cost is lower, I'm actually very happy about it. I just wish people would think longer-term and make the move. My system is a GE system, and panels have a 20(?) year warranty, inverter is 5 years. Even if the payback period is 10 years, you still are warrantied on the panels 10 more. I'm not sure what the inverters run, but as long as it can handle the capacity of the solar array, I'm sure there's a lot more options out there now and will be even more in 5 more years.

I should point out, the solar panels on those wooden poles, was in a specific city I drove through, not so much the state as a whole. I apologize for not clarifying in the original post, I was hurrying because I typed it up at work. Either way, a 200 watt panel on a post times many thousand posts in a state, adds up quick and gives a lot of production stability during the peak summer months when demand is highest. To add a couple MWH of potential generation during the middle of the day only makes sense, IMO.

I looked at getting a roof mounted wind turbine, but don't want to make another expense right now. I'm also worried that the trees in the neighborhood would make it not very feasible as far as production. They have them down in slower-lower, but it's mostly open land and lots of farm land so no wind breaks. My brother lives down there, and the wind is essentially non-stop blowing.

 

^^ I read recently a detailed report of a home windmill that was almost non-productive. Siting at low heights is a real gamble.

 

Agreed. That's my concern, too. Even roof mounted, it's only about 20 feet off the ground. That's not such an issue for some of the vertical axis ones, as long as there's not many obstructions in the way.

I agree, it's a great way to put people to work. It may not help lower rates, but it may help prevent the need for building additional power plants. Or you could begin to de-comission the old coal ones, and make a big dent in emissions. If we start now, imagine how much solar generation could be done in 5, 10 years.

 

The general consensus is that small scale (residential) wind is a loser. Most people over estimate thier wind potential, but the irony is if you have enough wind to be truly useful, you have too much. Most small scale wind machines live in a harsh environment, re not easily serviced and are full of mechanical loads that tear them apart. The stories of people becoming disenchanted with small scale wind are legion.

Icarus

PS roof mounted wind is also a bad idea, not just because of the fact that it is not high enough, and it has issues with turbulence from the roof, but because they induce a to of noise into the structure. Have you been in a house with an old fashioned TV antenna whistling in the wind? Add in the vibration and I'm guessing the house would be a nightmare!

 

With retail raw panel pricing under $1.50 a watt (retail) it is almost a no brainer for utility pole installation. 200 watts would cost $300, Enphase inverter under $200, mounting hardware $50. Engineering amortized over thousands of basically the same installs, might cost $.10, .5 man day labor at (wag) ibew rates, $300( could be done during otherwise down time keeping crews and equipment working efficiently) so an install would lead t a total installed cost of $850 or $4.50/watt. Buy panels by the container load, andthe price drops below $1/watt. By inverters factory direct, and the price would drop. I would guess you could get to a $2/watt install on the pole sytem. Factor in tax credits, other incentive, and I would guess you could end up with a net cost of $1!

Just start counting the poles in your neighborhood!

Clearly there are other issues I haven't consided, like metering (but since the utility is selling to itself, why does it matter? )

Not a complete solution, but surely a cheap start!

Icarus

PS. In our neighborhood we have a similar installation, but it is truly stupid. For 1 mile of public street, they have solar steet lights every ~100'. sounds good right? Well, not really, because each light pole has its own battery, (leading half the Efficincy and rice the cost! ) even though there is grid power on the same street! Not to mention that they have to budget to replace the battery at some point, adding additional service cost. Why someone with some experince was consulted before they did this is beyond me. A side note, it was on Native Indian Reserve and I'm sure there was some federal involvement. Smart choices should be truly smart, not just apear smart!

I

 

They could use a central battery for emgency back up, or a number of them, but to power them from battery based PV is just plain silly,, and expensive! I do know a it about battery based PV, as I design and install small off grid systems!

Icarus

 

They are self contained LED units, sort of Ike these:Solar Street Light (S-SL12)- Greenshine New Energy Co., Ltd.

Similar models have a 250 ah AGM battery. At the best of circumstance you are losing 20% Ef just by charging the battery. Add in the losses of unused power when the batteries are full or near full, and I bet the net Ef is closer to 25% which is just plain silly! (since the grid is right there,, along the same stretch street! )

While I guess there is some PR value in "showing the flag" so to speak, why not do it efficnctly? It is sort of the same old same old!

Icarus