Home Solar panels

Solar power works better for some than for others, and it depends on multiple variables, such as where you live, your current power rates, what source of energy does your local power company use...... there is no one answer for everyone.

Consult a reputable solar photovoltaic installer. He or she will do a site survey that calculates the average amount of sunlight you will get at a proposed site, usually your roof but not always. With a base estimate of sunlight exposure, the next item would be to do a power consumption estimate on your house. You can save huge amounts of energy by using CFL lights, turning off remote controlled appliances and computers, and replacing even relatively new appliances with new ultra efficient ones.

Once the solar folks figure out what your household consumption would be, on average, they will design a system for you depending mostly on your budget. Solar systems consist of two primary elements, the panels and the inverters which convert the solar DC to AC to operate in conjunction with your city grid (this assumes you are considering a "grid tie" system). You can't just buy a bunch of panels and install them because the power requirements/capabilities of the inverters have to match the output of the solar panels.

Grid tie systems generally allow you to be, in effect, reimbursed by your city power company anytime your consumption of electricity drops below what is being produced by your photovoltaic array. In summer here in Seattle, our system is enormously efficient leaving us with electric bills of about 5 bucks a month and this is for an all electric house. Winter, of course, is a wash because we use electric heat and don't get as much sun.

Overall, our system has cut our electric bill in half annually.

Solar water heating is much more efficient than solar photovoltaic systems because the water or coolant is heated by infrared and works well even on cloudy days. Our water heating system makes a huge difference
in our electric bill because the water in the holding tank never gets lower than room temperature so we use city energy only to heat the water from room temp to desired temp. Again, in summer, the water heater never goes on at all.

If you live where your electrical energy is produced from burning fossil fuel, going Solar will pack a double whammy. Think of it as paying now for energy you will use in the future. Energy costs will only continue to rise and solar, once installed, continues to produce energy at a flat rate.

Contact me off chatline via email if you want any more info.

 

Bob, you changed your handle you devil. I thought that was you when you mentioned your solar thermal system. What's the capacity of your hot water tank? It seems to me that solar water heating is about as low hanging as you can get for emissions reductions. It really should be a building code item. It seems madness not to put the collectors on all new construction. Gov't should be pimping the hell out of this technology considering how much NG it would save us. For electric water heating it seems like a no-brainer.

 

<div class='quotetop'>QUOTE(Tadashi @ Mar 2 2007, 08:56 AM) [snapback]399018[/snapback]</div>

That's a good question, I've been wondering the same thing. This is the tax form, but I need someone to interprete the legalese in it:
2006 Federal Tax Credit
http://www.seia.org/getpdf.php?iid=21

I'm going to try to do more searching on it. It was my understanding that whatever portion of the $2000 credit you didn't use could be carried over to 2007.

 

<div class='quotetop'>QUOTE(Tadashi @ Mar 2 2007, 07:56 AM) [snapback]399018[/snapback]</div>

My take on it is you'll get a credit (30%) for what you actually spend on the system in FY07. It's a $2k max total (right now). Who knows what might happen for '07 taxes?

 

<div class='quotetop'>QUOTE(tripp @ Mar 1 2007, 08:38 PM) [snapback]398832[/snapback]</div>

I've been debating this or getting a tankless (on-demand) system. We use natural gas here, so I'm not sure that solar thermal would pay for itself as quickly as a tankless system would. In theory, we could pre-heat the water with solar, then use natural-gas on demand to bring it the rest of the way if needed, but then we'd be adding both installation expenses.

 

<div class='quotetop'>QUOTE(nerfer @ Mar 2 2007, 09:17 AM) [snapback]399091[/snapback]</div>

Yeah, from an ROI perspective it's less effective if you're using NG, which is what we'd be displacing. The one caveat is that NG prices are WAY more volatile than electricity prices and there's a lot of upward pressure on the price of NG. So looking 5-10 years ahead the economics of it probably a bit better. Here in CO we have a lot of sunny days so I bet we'd drastically cut our water heating bill. However, a PV array might have a better ROI because we have a pretty solid rebate program.

 

Hi there,
I am responding to this thread with just some general thoughts. My apologies if things are repeated.

We are in Santa Cruz and had our 2.5 KW system since 2005. Our true up cost (difference between electricity $ generated and electricity $ used) has been:

2005 Electric bill $88.00
2006 Electric bill 102.00 (the boys leave the lights on )

The whole system was $25k, fully installed and ready to use. I received an $11k rebate, plus a one time $1800.00 tax credit, bringing the whole system to around $12k.

Our electricity bill used to be around $1000.00 per year. So if stay in the $100.00 true up range, we should recoop our investment in about 14 years (12 years to go !)

I recommend looking at a 3 KW system, if you can afford it. This should generate more then enough credit. I also recommend doing the Time of Use (TOU) metering. That means you day is divided into time zones where electricity is more expensive (i.e. day 12:00 - 5:00pm, evenings 5 - 7pm) when the demand on the net is the largest. It may take a bit of a life style change, i.e. don't do laundry between 12:00 pm and 7:00pm. It works well if you have a washer and dry with a timer. For instance we run the dishwasher around midnight, when electricity is the cheapest and the noise doesn't drown out conversations in the kitchen/living room.

Our Washer and dryer have a timer, so laundry is either done in the mornings or at night, starting when the TOU is best.

Replacing light bulbs with fluorescent bulbs does help a bit, as does an either super insulated water heater (best if you can have it in the garage with a blanket) or an on demand water heater. If you are thinking solar water heater, investigate and invest in a system that is smart on cycles the standing water in the tank when the temperature of the roof water is +15 degrees warmer. This should also drain the system at night, if you are in frost zone.

As far as the water heater is concerned I would look into an electric on demand heater. I know sounds scary, but with the extra .5 KW (going from 2.5 to 3 KW) you should be able to make up the difference easy and you are not subject to any gas price fluctuations. Having said that, we are still using NG, I am going back and forth on what to install next...

 

My rebate was the California rebate, I actually had to wait a year before getting my installation, due to a panel shortage. In that time my rebate dropped from $12.5 k to $11 :-(

You can look on the Gaiam site for general types of fluorescent light bulbs (shapes, wattage etc), they even list some for dimmers and recessed lighting. I have read (but not found again..sorry) that they are now selling natural spectrum fluorescent bulbs, which should make things a bit more cozy.

I have also one (1) LED bulb (it has about 60 tightly packed LEDs) in a recessed fixture. The light colour is something you have to get used to.. it is very crips and clean, but it uses about 5% of the electricity

You can check out: http://www.superbrightleds.com/led_prods.htm for LEDs
Of real interest may be those listed here: http://www.superbrightleds.com/MR16_specs.htm
Note that these are still considered "accent" or "low light" light sources, but they are getting there

While on the topic of light, I found this very interesting and educational:

http://home.howstuffworks.com/fluorescent-lamp.htm

 

<div class='quotetop'>QUOTE(Lywyllyn @ Mar 9 2007, 03:24 PM) [snapback]402964[/snapback]</div>

Yes, I bought a few of those "Daylight" CFL's at Walmart last week to replace the other ones in our clothes closets. It is too hard to distinguish clothing colors with a normal CFL.

 

<div class='quotetop'>QUOTE(nerfer @ Mar 2 2007, 08:17 AM) [snapback]399091[/snapback]</div>

Most of the energy savings with tankless heaters is actually due to not having the tank ... no store of hot water to radiate energy out of the system when you don't need hot water. The efficiency of the boilers in the tankless heaters is relatively low ... 82% or so ... so the install cost of a tankless combined with the large tank you need for solar is probably not a good deal. You can get some higher efficiency units ... you can tell these are high efficiency because they condense and you have to do something with the condensate ... but the cost is high. And the efficiencies are lower if you introduce already-hot water into them ... at 100°F, the efficiency is not at the 96 - 98% they advertise, but more at something like 90% IIRC. Again, the cost/benefit ratio is not there.

 

<div class='quotetop'>QUOTE(fshagan @ Mar 10 2007, 01:49 AM) [snapback]403212[/snapback]</div>

We have tankless and like it...BUT I have read that the tankless save energy primarily in settings where hot water is needed relatively infrequently. In other words, if the family is small (and maybe especially without teenagers), so showers, dish washing and the like are less frequent the tankless can save a bundle. On the other hand if the water is used often, every day, the tank type will be almost as efficient, and of course less pricey.

Jim

 

Tadashi, I would get a couple of bids on installing a 2.5 kw (minimum) or 3.0 kw system. I would also apply for the rebate NOW, as there is not telling how much money will be left in a view months or longer. We lost some money, simply because we had to wait with the installation due to material shortages.

Also the solar company doing the bidding and potentially the installation for you can, as done in my case, bill you for the difference in price, when the solar company applies for the rebate in your name. In other words, our system was billed at $25k. The rebate was filled out by the company and myself. The rebate arrived and was cashed by the solar company and I was left with a $14k bill

The solar guys/gals will also be able to tell you what you can add on later, it usually requires more permits and installation fees and it might cause ruffled feathers with your local utilities company. PG &E for example does not like to see systems above 2.5 kw...

 

I have a tankless water heater and I like it but installation can be problematic in older homes. Firstly, on the high install costs, is to have at least a 3/4 inch natural gas line from the meter all the way to the hot water heater with nothing else on that gas line. When the tankless units fire they require a LARGE amount of NG and you need at least a 3/4 inch line dedicated just for NG volume. In older homes especially those built before about 1990 or so the gas feed line to the utility closet is usually 3/4 and that includes the furnace and hot water heater as well as dryer and perhaps a gas stove too. You will need to install a new dedicated gas line from the meter to the on demand heater at least 3/4 inch depending on the requirements of the tankless heater you buy. While the heater is easy to install it will require a temperature and pressure relief valve as well as a condinsate drain from the flew. Not all municipalities require the condinsate drain but it is a good idea. The gases are hot and in winter where you have a cold outdoor temperature the inside if the flew will condense and and without a condinsate drain all that condinsate drains right back inside the heater. Not good with all the electrical stuff in there. Most tankless heaters now also require a dedicated 120 volt branch circuit too just as is done for your furnace. So, the gas line and the electrical circuit need to be figured into the installation costs.

Lastly, the flew is big time money on a modern tankless heater. They are made of single wall stainless and have special neoprene seals built into the flew pieces. I generally figure 35-70 dollars a foot for tankless flew depending on the complexity of the run. The unit itself is also expensive retailing for between 1500$ to 3500$ depending on capacity. One advantage the tankless heaters have is the flew need not be run vertically. Because they have high rate of fire they are power vented using a blower to move the CO out through the vent so long horizontal runs are OK and some units are OK to be mounted outside too helping with cramped utility spaces.

I agree that minimal use hot water environments are best for their use, they can and do save energy even when used frequently. Their projected life is supposed to be 20-25 years so they should outlast a conventional tank heater but none have been in place that long here in the states so, we have no first hand knowledge of that here. In japan and Europe where they are commonly used, however,they do suggest a long life but they need to be serviced more frequently then a conventional tank heater. The single biggest complaint with their use seems to be frequent fluctuation of temperature for no reason. Frequent cleaning of the intake screen is essential in preventing temperature fluctuation and easy to do. Scale build up within the heating coils can cause problems too and there is a flushing procedure that needs to be followed every 2 years. Most people would increase the life of their conventional tank heater too if they followed its instructions that call for draining and refilling the tank once a year but who does?
-Paul R. Haller-

 

Check with HOME DEPOT.
here they are working with BP energy, so you have 2 bigs names that won't disappear overnight. If TX has any incentives, they will know about them and do all the paperwork.
NJ has a great program, I applied today but it takes awhile to get hooked up. You may also need to upgrade the service panel to your home.

 

<div class='quotetop'>QUOTE(barbaram @ Mar 12 2007, 02:53 PM) [snapback]404413[/snapback]</div>

Check with the BBB before you contract anything through Home Depot! Like Sears, they use subcontractors, and I have heard horror stories about their subs.

 

Oh well then.... I found this:

http://www.eere.energy.gov/greenpower/mark...tmetering.shtml

a couple of PDFs Texas is listed there. So unless you are not receiving your energy from those providers listed, they are lying and you should get names and dates and such.

 

<div class='quotetop'>QUOTE(Tadashi @ Mar 15 2007, 11:19 PM) [snapback]406524[/snapback]</div>

I believe there is Federal requirement for buying back. But net metering is not required, nor is it mandated that it be easy or economically viable. Most of that is handled by state legislation, and something like 35 states mandate net metering. In Michigan there is a net metering requirement in place for smaller systems but so far they have gotten around that (the utilities that is) by requireing a new meter if you intertie. Funny thing though, the new meter will not run backwards (even though oftentimes the old one would have). I don't know how they actually get away with that, but so I am told by those who have experienced this.

Jim