Hillsborough County is installing hundreds of solar panels on the county courthouse in downtown Tampa, a Hillsborough County official said.

According to a statement issued by county Energy Conservation Manager Randy Klindworth, "The installation is part of a large alternative energy project that Hillsborough County started last year...The solar panels will supply 40-60 percent of the building’s energy load when they are installed and save more than 322,000 kilowatt/hours in power. These solar panels will save the County more than $60,000 annually in energy costs."

The funding for the $1.3 million project comes from a federal stimulus grant.

Two hundred solar panels are going on the roof of the county courthouse on Pierce Street. The panels are 18 feet long, 15 inches wide and only about 1/6 of an inch thick (4 millimeters).

Break even is in 21 years assuming maintenence costs will offset rise in rate hikes. Is it worth it?

Our tax dollars have gone for worse things (hopefully the PVs are not Chinese)! It will save the County some money, eliminate a bit of carbon and it put a few people to work, so those are not bad things. 

The politics of energy has many facets. Last week, I met a venture capitalist who specializes in alternative energy. His position is that if governments eliminate the massive tax benefits and subsidies given to oil companies, alternative energy is very cost competative. That probably has as much chance of happening in the USA as an energy or carbon tax, although I believe higher energy costs would promote conservation (which is the best money spent) and stimulate investment in more efficient technologies. My view is that alternative energy is not THE solution to our energy problem.

Bruce

Alternative energy sources are certainly a PART of the solution, but I believe conservation is the most important single component. I think people really expect that technology will enable them to continue to consume energy in unlimited quantities. The good news is that technology can also greatly improve conservation.

An analogy is healthcare. People expect medical technology to cure their poor lifestyle choices. Medical technology can work wonders, but it is expensive and many healthcare issues could be avoided.

Let's hear it for personal responbsibility!

Bruce

What Bruce said, although I'd swap "efficiency" with "conservation". Conservation simply means doing with less at the load-end of the resource, but efficiency is a bit broader. Efficiency means lowering the load (more insulation==less heating/cooling energy requirements) as well as better utilization of the fuel resouce (a high-efficiency LED or CFL uses 1/5-1/4 of the power to produce the same amount of light as an incandescent bulb, heat pumps use 1/5-1/2 that of electric resistance heating, etc.)

Conservation also has an implicit personal responsibility aspect, whereas efficiency doesn't necessarily. If we're counting on a radical transformation of human responsibility to turn the tide (despite the historical record) we're sunk, but with mandated efficiency minimums for everything from light bulbs & refrigerators to building envelopes, not so much. Forgetting/neglecting to turn the lights off costs 1/4 the power with high-efficiency lighting as with old-skool goods. The amount of money it takes in PV + backup generator costs to make up the 3/4 difference is gia-normous compared to the costs of implementing the higher efficiency load. Putting the light on occupancy or daylight-sensor control to keep it from being wasted is similarly cheap compared to the cost of the PV it would take to fill the wasted operation at the load, and further factors out the personal responsibility part of the equation.

At the current state of overall grid & electrical load efficiency in the US you can buy a HELLUVA lot more kilowatt-hours with efficiency per dollar with existing technology than you can buy with adding solar, nuclear, (or even cheap coal) generating capacity. Solar arrays make a visual statement of intent, and may/may-not have been the next-most-cost-effective thing to do for offsetting energy use with that at the Tampa county buildings, but I doubt it. Fortunately in Hillsborough County the amount spent on PV array for the courthouse isn't even half the amount of the total block grant, the rest going toward other efficiency upgrades on several county facilities:

http://www.tampagov.net/information_resources/recovery/news_county_receives.asp

By many analysis the lifecycle cost of "nega-watt" efficiency measures is under 5 cents/kwh, whereas PV is still over 25 cents/kwh. But it's a lot harder to see- doesn't make much (or any) visual impact.

Similarly, getting dramatically higher fuel utilization using fossil-fired cogenerators supporting thermal loads like hot water heating/space heating also flies below the visual radar but has a much higher impact per capital-dollar spent than PV. And unlike PV, is an inherent load balancer for the grid as a whole during the heating season in heating dominated climates. A fleet of space-heating cogens will supply electricity in proportion to the regional heat load, the same proportion drawn by all of the heat pumps & resistance heaters in the same region. In Tampa the peak air conditioning loads are only partially offset by PV, since peak PV output leads typical AC peak by a few hours (with smart controls some amount of pre-cooling can better align PV output with peak air conditioning loads though.)

Still, simply putting the solar panels up there shades the roof, lowering the cooling load, and reducing wear on the roofing material, extending it's life. Lifecycle costing rooftop PV arrays isn't as simple as calculating utility cost offsets.

We'll need it all, but spending more on efficiency is currently (and likely for the next decade or more) a better investment than PV power generation. There are no single magic-bullet solutions, but removing 1/2-3/4 the load is an important first step for making green-power affordable, and it's not pie-in-the-sky dreamland technology to get there- it's the boring stuff like insulation and "cool roof" paint, duct & air-sealing that will be doing the lions share of the transformation.

Posted By Dana1 on 04 Oct 2010 05:45 PM


Still, simply putting the solar panels up there shades the roof, lowering the cooling load, and reducing wear on the roofing material, extending it's life.

Dana1;

You sound like a PV salesman,    while shading the roof would help the UV  deterioration on the roof you need to consider that by adding the panels you have added many penetrations to the roofing making it more prone to leakage, makes it more problematic when replacing in that the panels would need to be removed and replaced adding to the overall roof replacement cost.
I think PV panels being beneficial to the roof is a stretch

No seriously, the PV panels could shield that part of the roof from meteor showers, too.

Posted By cmkavala on 04 Oct 2010 06:03 PM

Posted By Dana1 on 04 Oct 2010 05:45 PM


Still, simply putting the solar panels up there shades the roof, lowering the cooling load, and reducing wear on the roofing material, extending it's life.

Dana1;

You sound like a PV salesman,    while shading the roof would help the UV  deterioration on the roof you need to consider that by adding the panels you have added many penetrations to the roofing making it more prone to leakage, makes it more problematic when replacing in that the panels would need to be removed and replaced adding to the overall roof replacement cost.
I think PV panels being beneficial to the roof is a stretch

And here I usually sound like a cellulose salesman!

The reduced cooling load is easily measured on flat-roof installations (I can google up some of the academic measurements of the same, if you like), but OK, the extended lifecycle of the roofing based on the lower operating temp is still largely theoretical.  Most larger arrays are done on steel truss structures to minimize roof penetrations & loading though- I don't think the additional penetrations and difficulty of roof replacement/repair is as much of an issue on big 200kw commercial building arrays as it is on 1-5kw single family residential rooftop installations.

It turns out in this case they used flexible roofing-integrated PV panels anyway (the roofing IS the PV), so those aspects don't factor into the Tampa courthouse application the way they do on at truss mounted over the membrane roof on a Nevada Wal-Mart.  The elevated temp of being integrated into flexible roofing panels on the Tampa courthouse probably cuts into real-world performance too, with no back-side convection cooling it'll be toasty enough to run well below their 25C output rating due to thermal electron leakage.  (I'm sure the designers factored that into their annual return estimates, along with performance loss due to pigeon & gull poop shading, etc. .)

If you read the whole post you'll discover I'm not a big fan of spending the money on PV- in fact it's quite the opposite.  I'd rather people & institutions spent it on natural-gas fired cogenerators on the power-generation end, and spent the rest reducing the load with efficiency measures.  (You can do a lot with a cogenerator fired absorption chiller too, eh? And it's more flexible in terms of delivering the heat & power when you need it.)

If/when Nanosolar and their technology-equivalent competitors go after the US market in a big way, THEN PV might show some real payback.  But at the moment the European subsidies are keeping panel prices high- high enough to soak up the entire annual production of the Nanosolar printable PV technology.  Their manufactured cost of goods is more than an order of magnitude lower than the current wholesale price for panelized PV (and well below the material costs for silicon PV technologies) Give it a few more years- building more printing presses isn't a huge slow capital undertaking, and the peak-gigawatts shippable per year will eventually only be limited by availability of Indium for the inks (it's a copper-indium-gallium disulfide or "CIGS" PV process.)  See: http://www.greentechmedia.com/artic...ology/

payback in 21 years?  Isn't the life of a PV panel not much more than that?

Posted By slenzen on 05 Oct 2010 09:14 PM
payback in 21 years?  Isn't the life of a PV panel not much more than that?

said break even,  not payback

Posted By Dana1 on 05 Oct 2010 06:29 PM

If/when Nanosolar and their technology-equivalent competitors go after the US market in a big way, THEN PV might show some real payback.  But at the moment the European subsidies are keeping panel prices high- high enough to soak up the entire annual production of the Nanosolar printable PV technology.  Their manufactured cost of goods is more than an order of magnitude lower than the current wholesale price for panelized PV (and well below the material costs for silicon PV technologies) Give it a few more years- building more printing presses isn't a huge slow capital undertaking, and the peak-gigawatts shippable per year will eventually only be limited by availability of Indium for the inks (it's a copper-indium-gallium disulfide or "CIGS" PV process.)  See: http://www.greentechmedia.com/artic...ology/

CIGS is the technology being pushed the most here in Europe.  Some subsidies are available ONLY for CIGS.

Politics and tax issues are alive and well in the European energy industries, too.

Bruce

It's no mystery why Nanosolar built their panelization factory in Germany, even if the production cell-printing presses are still only in the US. I'm sure the various capitalization deals were too good to pass up.

CIGS is heavily promoted since it's clearly a low-cost/high efficiency PV technology, on the order of 2-3x the efficiency of organic PV, and closing in on commercial silicon efficiency (but at a much lower manufactured cost). Subsidizing it to help capitalize higher production capacity is probably the near/intermediate term strategy, since it's mid-to long term prospects are so likely to become cost-effective.