New looking to go solar

Re: New looking to go solar

The reality is, at least for the foreseeable future, if you have utility power, going off grid will not be cheaper or greener.

Building a small off-grid system for experience is one thing. To expect to expand it piecewise is another.

Generally, it is very difficult to "grow" an off-gird system (and even a grid tied system is somewhat difficult to "grow" too). The components are not cheap--and they tend to match in size/load characteristics... I.e., you cannot run a 6kW 48 volt Hybrid GT/Off-Grid Inverter on a couple of RV batteries. And, you cannot mix your old+new batteries very well (the new batteries tend to age to the existing bank and die young).

Your better investments... Conservation... Insulation, energy star appliances, windows, ground sourced or high SEER A/C., CFL lights, turn things off you don't need, etc.

Next, solar hot water (domestic hot water, and possibly area heating).

Following up with Grid Tied solar. Cheapest and most reliable of the solar electric solutions. However, does not provide off-grid/emergency backup power. A good backup generator with transfer switch may be a cost effective backup power source--if needed.

Or, a Hybrid Grid Tied Inverter with off-grid backup power (really only makes sense if you are in an area which is subject to frequent and/or long power outages).

Off-Grid--really only if it costs you tens of thousands of dollars to get the lines ran to your home/cabin.

Just to give you some, very rough, ideas of power costs:

$0.10-$0.30 per kWhr -- utility power
$0.25-$0.35 per kWhr -- Grid Tied power (20+yr life; can drop by 1/4-1/2 with rebates/credits)
$1.00-$2.00+ per kWhr -- Off Grid system (20+ year life+maintenance)

At this point the costs of Off-Grid does not even come close to that of utility power. If you figure out the costs of the inverter/charger and battery bank (+replacement batteries every 3-10 years)--you are probably ~$0.45 per kWhr just for their costs.

A GT system costs ~$8 per watt (a 3.5 kW peak system which will generate ~5,000 kWhrs+/- per year), will cost ~$24-$30,000 installed.

An off-grid system, of similar power capabilities will probably cost 2-3x that amount.

Having an end-point in mind is a very good place to start... Is it to "go green", save money, preserve the environment, or what...

And, starting with conservation is pretty much the first target to aim at. Reduces power usage/costs right up front. And, saves in that what ever your end result is--GT or Off-Grid--those systems needed to offset/generate your power are much smaller too.

-Bill

Re: New looking to go solar

Assuming that your power bill is for A/C--Then you probably want to look at attic insulation and as efficient A/C unit as you can find (possibly ground sourced--if you have the room to lay pipe/drill wells).

If you need to circulate air for ventilation (my wife hates "stale" air)--a heat recovery ventilator might be worth a look for you too.

In California where I could be hit with a $0.58 per kWhr bill if I used that much power--GT solar does make real economic sense... If you are paying $0.10 per kWhr--then, at best, you may break even with GT solar (after rebates).

You really want to look at "extreme" cooling (and heating?) conservation measures.

By the way, reducing energy use inside your home/conditioned space can also save you on A/C costs... Old Fridge, big entertainment center, lots of decorative lights/ceiling pots/spots, several computers+laser printers left on all day, etc... You have to pay to remove all of that heat with your A/C... So, if you can reduce your internal loads, you save again by not needing to pump the heat outside. CFL's don't look pretty--but they really reduce the heat building in your home.

-Bill