Grid-Tie proposals recommendations

BB. wrote: »

Are the prices including the rebates? Also, will the vendor be responsible for obtaining the rebates, or will you (i.e., I paid my installer the post rebate price, and he had to file the paper work and wait for the government to pay the balance--not me). Have they provided any estimated monthly/yearly o

Backing up a moment--Do you have a good handle on how much power you use per month (by season)? How does your utility manage the billing (1 year net metering, 1 month net metering, credit you for the wholesale price of power, etc.)? Solar power is getting pretty close to reasonably price--But I would still recommend that you review your power usage and see if there are any conservation measures you can take that will reduce your power usage (energy star appliances, updating A/C and possible heat pump heating system, insulation, double pane windows, etc.).

The systems look to be reasonble size and pricing (under $5 per watt installed, before rebates, is usually a good price).

It would appear that you would be paying cash for the system--vs leasing.

The economy and the solar power market is not really great right now--And a fair number of installers have bit the dust lately. Your installer stable? My installation had a 5 year installer warranty (labor). A few people here are starting to have issues with their installer out of business, and needing to find somebody else to do warranty work (changing out failed inverters).

-Bill

BB. wrote: »

Your power usage does not sound that high (especially if you have any A/C or other large electrical appliances). If the TV uses a lot of power, then changing to a less power hungry version can save quite a bit of money (if your set is running many hours per day). A Kill-a-Watt type meter can help you figure out what appliances are costing you today (at least your 120 VAC plug-in devices).

Natural Gas prices should be dropping (or at least not rising), unless government gets involved and does the high taxes/carbon credit/local regulation type stuff.

But, if your gas prices are high--You might want to look at some new electric appliances that may be cheaper to run than the gas fired versions (especially if you add GT Solar).

A heat pump based water heater such as this one. Is probably 2-3x more efficient than the resistive version. The "waste energy" of these is cold air and dehumidification--Not bad for a warm island climate (something like $1,000-$2,000 continental US pricing).

And there are the Mini-Split A/C + heat pump units (if you need dehumidifcation and/or heating in cold weather). They are probably 2x more efficient than older A/C units. And can be 2-3x more efficient than resistive electric heat. (i.e., what if your electric costs were 1/2 to 1/3 of the $0.20 to run those appliances vs natural gas).

You can play with this fuel cost calculator to see what the numbers work out to be (don't fall in love with a solution--do the math first):

http://www.hearth.com/econtent/index.php/articles/fuel_cost_comparison_calculator/

-Bill

BB. wrote: »

Without knowing more details--It is hard to guess... But, say your natural gas prices is 2x mine:

2x $1.36 per therm (~1 CCF) = $2.72 per Therm

Electricity cost is $0.20 per kWH

From the Calculator:

Electric: $58.60 per Million BTU of Heat delivered to home
Nat Gas: $34.00 per Million BTU of Heat delivered to home

So, from a simple point of view, if the electric hybrid hot water heater is 2x as efficient per standard "resistive heating", then you would be saving a bit of money. If it is 3x as efficient (warmer climates, the hybrid heaters are more efficient), then you could save more.

The electric hybrid heaters have different modes--A high efficiency mode where it only heats with the heat pump (probably at a rate of 1,000 to 1,500 watts) or the high demand mode where they heat with traditional resistance heater (lots of people taking showers, etc.)--So in that mode, they are less efficient.

Regarding cooking, there are inductive cook tops and "hot plates" which are pretty nice (with the correct pots). You can try a "hot plate" induction cooker in your kitchen and see how you like it. I tried one for some cooking and it worked fine--However it was supposed to be around 1,800 watt, and using a Kill-a-Watt meter showed only ~1,300 watts maximum power from the outlet--So, they may not cook as fast as they could.

Also, if you are into stews, rice dishes, etc. that take a long time to simmer (or even use a "crock pot")--A popular cooking accessory is a large thermos. They work great--We just place the pot on a stove, bring the meat (or whatever) to a boil, and throw it in the thermos for a couple hours, and reboil if longer cooking time is needed). Not cheap, and in our area, you can find them at the local Asian markets. Again--reducing the cost of heat to cook, and reducing heat released in the conditioned space.

Assuming you need A/C (at times) for cooling--Reducing heat into the home via stove, old TV, etc. can reduce your cooling costs too (plus if the hybrid water heater is in a conditioned space, its "waste" is cold air.

At this point, one of our posters here (Solar Guppy) believes that the hybrid water heaters are actually more cost effective than pure solar thermal--Given that you don't have solar thermal panels, pumps, extra water storage tanks, maintenance, etc.)--Pumps, leaks, freezing weather (probably not an issue for you), air leaks and air locks in piping, etc. are all real issues.

If you want to still look at solar thermal panels for hot water/home heating--I really like this guy's website. He goes through the detains of design, installation, and debugging/redesign when he hit all of the issues that everyone finds on their first project.

http://www.arttec.net/Solar/BarnHeat.html

From this thread:

Solar Shed and other Solar Thermal Links

-Bill

PS: I should add that you need to really study your power bill and various options (time of use, seasonal pricing, net metering).... Every place is different.

Some will install one meter--And at the end of the month, will charge you (or credit you) based on the reading (i.e., if you use lots of electricity at night, but generate a bunch during the day, the net amount after 1 month--or 1 year). Others will install two meters. One to charge your kWH per month usage, and a second to pay you your kWH per month generation, etc...

Depending on how your utility bills (and various billing options you may have), can dramatically affect your choices and eventual system.

Another question I have--You mentioned inverter sizing vs your loads... For Grid Tied systems, the sizing of the inverter is just to support your array size. YOu do not need to size your GT Inverter based on your peak loads--The power will be supplied by your utility and the GT inverter just injects the power it receives from the solar array into the home wiring system... More or less like your car's alternator. And the utility looks for all the world like a giant AC Battery Bank.