[TheForge] solar systems

[John Switzer]

My home and therefore blacksmith shop are off grid with solar power as a 
primary source of electricity.  I missed the original post, so I hope I can 
answer the question.  The key to keeping costs down with solar energy is to 
conserve power a watt saved is a watt you don't have to generate or 
store.  We have a small house and keep our power use low when 
possible.  Compact florescent light bulbs use 1/4 the power of regular 
incandescent and we have a very high efficiency refrigerator.  We don't use 
any electrical heating (except the toaster oven and wifes hair drier) this 
means gas oven (also a wood oven) gas hot water gas clothes drier and gas 
heat.  Before you can know what you need for solar or wind power you must 
have a good idea of your power needs.  This will require that you find the 
power consumption on every electrical power draw you own and figure out how 
much they are used.  Check out Home Power magazine on-line, I think they 
have a  spread sheet that will help with the calculations.

Jim quoted a price of 250,000 for 5000 watts just for the solar panels, I 
think he dropped a decimal point.  Most panels are around $5 per watt. That 
makes it more like 25,000.  The good news is that a home and small shop 
would need a much smaller system.

Our solar system consists of 10 - 75 watt panels for a 750 watt solar 
array.  During the winter when there is little sun this provides about 3500 
watts of power.  We have a 1200 amp hr battery bank at 24 volts thats about 
14,000 watts of power that can be used when the sun is not shinning or 4 
days worth.  We use a modified sine wave inverter to convert 24VDC power 
into 110VAC power, this is a 3600 watt inverter so you can have a 
continuous draw of 3600 watts at any given time or 7200 watts for a short 
period.  The inverter is rated at 30 amps so for all practical purposes 
that is the power we have available (most new homes have 200 amp 
service).  To live on solar power you must conserve power and must watch 
your meters to know how you are doing, just like the gas gauge in your car. 
Or you must spend huge amounts of money to put in a system that will handle 
blind use of power.  Our system probably cost around $10,000 and might be a 
bit less at todays prices.  This is roughly the same that it would have 
cost to run power to our site.

The shop uses the same power from the house and is currently supplied by 
one long extension cord, hopefully this summer I will et some power lines 
run from the house.  We only run one or two tolls at any one time.  The 1 
hp motor on the 25 lb little giant runs just fine as does the 2 X 72 Wilton 
belt grinder.  Forge blowers, drill press and band saw all use less power 
and two of those can be run at the same time.  Shop tools are a case where 
you must pay attention to what your system is doing.  Is the system full 
enough to run the tools? is the sun shinning? do you want a certain amount 
of power left to use lights in the house tonight? ost of the year we don't 
have any restrictions in the shop.  There are days when you have to budget 
power use and change your work habits to suit the weather and power 
production. We do have a Lincoln Ranger 250 welder /generator that we use 
for back up power to the house or shop and it provides stick, MIG and TIG 
welding power.  This is also what runs the 2 hp motor on the 50 lb little 
giant.  The 125 lb Bull hammer runs on a 20 hp gas powered air compressor 
and has no effect on household power.  Of course human powered tools have 
no cost in electrical power so we have a treadle hammer and a fly press.  I 
must admit that the shop would be more efficient with grid power, but the 
freedom of being your own power company makes up for it as far as we are 
concerned (especially when a storm knocks the power out).  We hope to add a 
pair of stacked sign wave inverters in the near future, this will provide 
30 amps at 220 and then the 50 lb little giant could be run from the solar 
power system.  You could in theory stack enough inverters and have enough 
solar panels and batteries to run 3 phase 440 equipment, but that would be 
very expensive.

If power lines are close you can have the best of both worlds by using a 
grid intertie system and then the power company buys from you when you have 
extra and you buy from them if you need more.  If I had it all to do over I 
would still chose solar power.

John Switzer
Beulah, CO
www.blackbearforge.com