BP, GE, Kyocera Solar Panels

System

We are a condo association that has townhomes built in the 1960's here in Atlanta. We have 39 condos that use one air conditioning abd one heating system. The system pumps water either hot or cold into our homes and we have our own electric to pump either A/C or heat into each of our units. We were told by a Solar Energy Company that they could install GE and BP solar panels that would completely run all our electric from this one huge A/C unit. It takes 3750 kwh of electricity every 120 days approx. Is this feasible? Can we really install a system that will end our dependence on Ga Power. This will be a on-grid system. Seems to good to be true! I got on line to a firm in California who is recommending a Kyocera solar system. Are we crazy to think that we can really run A/C and heat for 39 townhomes totally on solar?

niel

Re: BP, GE, Kyocera Solar Panels

sarrett,
with enough money and if you have the room for it, nearly anything is possible. 3750kwh/120 days breaks down to 31.25kwh/day. you have 39 units so this is about 802wh/day per condo unit. is that actually all that each unit uses for hvac as that is doable? you actually won't do away with the utility, but you will just be feeding the power you produce to their part of the grid system and thereby offsetting the bill. i don't know what provisions your state makes for grid-tied systems, but you can check your state at www.dsireusa.org and, who knows, some of this might be rebated back to you for the costs of the system. some tax deductions(if that's the right way to put it) are also at the federal level.
read up on the proposals they make to you as to who gets rebates if applicable and know exactly what it is they are proposing to do. you can run questions past us on some aspects, but i can't say we are experts when it comes to rebate laws as it varies state to state.
i'm not sure if i missed it or not, but is that 1 big heat pump for all of the units? is it geothermal as those systems are said to be very good, but for a geo system that big would encompass allot of land area?

BB.

Re: BP, GE, Kyocera Solar Panels

It does not sound like it would be impossible at all...

However, I sort of wonder if you have the power usage correct at 3,750 kWhrs per three months? In hot climates, it is not unusual to run 2,000+ kWhrs per month for one home's A/C.

Anyway, the basics, first--conserve--it is almost always better to spend your money on conservation first (both on your central system, and at each of the 39 units before you try to make your own power). If this is an old unit--it would behoove your association to talk with a HVAC contractor about the efficiency of the current system. In general, if it is more than a decade old--you can probably save a lot of energy (1/3-1/2?--I am not an A/C guy) with a modern energy efficient unit.

Also--adding lots of insulation (R19+ walls, R40+ roof, adding double pane vinyl windows, energy efficient appliances, lighting, etc.) all will dramatically reduce power needs (and reduce A/C loading in the summer).

Next, check with the Electric Utility about their rules for net metering for your common area A/C-Heat system. In California--there are a whole set of rules for Net Metering and there is a huge difference between single family and larger businesses (I don't know where your plant would fit). In California, commercial systems are charged both for power and for "reservation charges" (basically, about 1/2 the bill is kWhrs used, and the other 1/2 is your maximum 15 minute power usage over the last year). For commercial--in California--it is possible to have full Grid Tied solar--but only cut the bill by 50%. So--knowing how your utility will treat/bill your installation is critical (and if it would even allow GT connection). By the way, get everything writing--on company letter head, signed by somebody who will have power to implement the agreement.

Next, there are tax credits and rebates available--you can start here to see what may be available in your area.

Next, how much power do you need... You don't have to offset 100% of the power--but I will make a guess that for 12 months of the year will match your usage--of course, you can make your own choices.

3,750 kWhrs per 3 months * 4 quarters per year = 15,000 kWhrs per year

Go to the PV Watts website, pick Atlanta Georgia, and enter 1 kW of solar panels (easy to scale). Leave the defaults for everything else... And you get:

Results For Atlanta G.

Month
Solar Radiation (kWh/m2/day)
AC Energy (kWh per month)
Energy Value ($ @ 7.9 cents per kWhr)

1 3.86 90 7.11
2 4.67 97 7.66
3 5.21 118 9.32
4 6.17 133 10.51
5 5.95 129 10.19
6 5.81 119 9.40
7 5.82 121 9.56
8 5.83 123 9.72
9 5.21 108 8.53
10 5.51 122 9.64
11 4.42 97 7.66
12 3.72 87 6.87
========================================
Year 5.18 1345 $106.25

OK, for 1 year, 1kW of solar panels on a Grid Tied System in Atlanta will generate ~ 1,345 kWhrs per year... Take your yearly power needs and:

15,000 kWhrs per year / 1,345 kWhrs per year per 1,000 watts of solar panels = 11.15 kWatts of solar panels...

That is not that large of system... And they may charge you $6,000-$10,000 per kW of system size (~$70,000 to $110,000). Now, you may be able to cut the costs by 30% or more depending on Federal and local tax credits, rebates, and other programs...

The above is a very quick and dirty estimate--and I am not in the solar contractor or retailer/wholesaling business--so take my price estimates with a very big grain of salt.

Now--how much are you paying for electricity? Is it $0.08 per kWhr or is it $0.30-$0.58 per kWhr (in California, our peak rates). You may just about equal the cost of your power with GT solar and current electric rates (also depends on property taxes, interest rates, etc.)--$0.08 per kWhr is hard to beat with solar RE.

$3,750/3 months * $0.08 per kWhr = $100 per month power bill

And--notice--you are not ending your reliance on Georgia Power--you are just (hopefully) fixing your energy costs for the next 25+ years. A grid tied system will turn off (for safety reasons) if the utility power is loss (there is no blackout protection with GT solar).

Questions? Does this help?

-Bill