NOFA-NY 2012 Winter Conference Presentation
on Fox Creek Farm's Off-Grid electric systems and ideas
(Raymond Luhrman, 1/21/2012)
IMPORTANT DISCLAIMER: While we did all the work on the renewable energy system on the farm ourselves, working with electricity is inherently dangerous - let alone, raising a 100' tower with a 1kW wind generator on top is not something that should be taken lightly. Making your own electricity from sun and wind is surely do-able, but please keep in mind your own skill set and comfort level, and consult with a licensed electrician when needed (which may also be a requirement based on local building and zoning regulations)
(BACK TO FOX CREEK FARM WEBSITE)
Farm from the air - when we found our farm in 2003, there were few improvements and no electricity. A fast National Grid quote from their measurement crew on a frigid January morning set our budget for our off-grid electrical system ("That will be about 40k, above ground, that is").
Down on the ground it looks somewhat like this
Off-grid electricity does not come with incentives - no NYSERDA grants, USDA programs or what not - so you're out on your own, more or less (also, without the grants you do not need to work with a certified installer). Off-grid electricity is not cheap, and every watt not consumed is a watt you don't have to pay for designing your system. For a household system there are electives: not to watch TV or delay the laundry until a sunny day. For our farm, we need to run our walk-in cooler, and run our well pump. We choose most energy efficient options for this, and modify upon that.
For example, our walk-in runs on an energy star air conditioner controlled by a CoolBot (www.storitcold.com) - for the well pump we had or well guy search for the most energy efficient option available. Our home refrigerator is a SUNFROST (which at times helps us store early harvests of peas, for example)
The EPA website has great tabulations on energy star products -- note that there is energy star (at least 10% below government standard) and energy star (that is, much less energy consumed than the 10% less than government standard). It's worth checking and comparing!
Our first solar array, Top of Pole, 8, 175 W Evergreen panels (in 2006 still made in the MA, USA). Installed ourselves with help from the manuals that come with the components, and the book 'Wiring Simplified' - also, much information from Home Power Magazine (a must read in case you are considering setting up an off-grid system, if it was just to see what others do and to get an idea about the vendors in the field). Since there are too many variables to figure out how much electricity we would be using given the new walk-in cooler and our growing farm needs for the same, we figured the sizing of the array by trail and error. Our first trail was limited by our financial means - thus this 1400 W array.
Our power room. 24V system, mostly Outback components. Windmill controller comes with the Bergey XL 1 we put up in the fall of 2007. Batteries are lead-acid DEKA L106 - in the box, power vented to the outside when the battery voltage goes above 26 volts. From the inverter on, everything is back to normal (i.e. from the 120 VAC breaker box, everything is wired just like a regular home).
After our first year we found out that the solar array would not keep up with our needs - we were running our back-up generator way more than we would like. With the wind on the site we decided it would probably be good to put up a wind generator. We went as high as we could (100') with a small Bergey XL 1 (rated at 1kW, 24 V). With help of a lot of friends, we got the windmill up in a couple of hours (excluding the digging for the ground anchors and running the wire from the windmill site to the barn - which took quite some more time). We purchased the windmill through Backwoods Solar - they specialize in off-grid electrical system supplies.
By being off-grid, there are no grants coming from NYSERDA or USDA for putting up small wind generators on the farm, either.
With the instructions that came with the product, we managed to install the windmill without trouble ourselves.
'and up it goes'
The more wind you got the better - on marginal sites it is probably not a good idea to put your money in wind! We did not set up a test tower. It would probably have cost as much to raise the test tower as it would have to put up this small wind generator. But if you would go with more expensive equipment, it is a good idea to make sure the machine is going to pay for itself at some point in time by doing testing!
Three years later yet (2011). The farm has expanded its CSA to well over 200 shareholders, and we found out that with the wind and first solar array, we still needed to run the generator about 1-2 hours a harvest day to keep up with demand. Since the generator is a 3000 W outfit, we knew that our budget was about 4 kW/day short. With the raising gas prices (and what is sustainable about using up non-renewable resources, anyways), and a sharp decline in the price for solar panels (about 1/2 of the price in 2006), we added another array of six, 220 W Schott panels, totaling 1320 W (made in USA, again purchased through Backwoods Solar). This time we build our own mount with angle iron and lumber, to offset the increase in price for the top-of-pole mounts (and shipping).
We added an Outback charge controller to take care of this extra capacity, but are still using the same batteries and inverter. Adding on therefore is relatively cheap.
In April of 2011 we had our first 'power out' since 2006 because of lightning strike. Despite the lightning arrestors on the windmill, solar arrays and generator input, it whipped out the electronics in the inverter, some of the peripherals, and a diode in one of the charge controllers. Outback was very good in helping us out getting back our power: the strike was on Tuesday and by Friday we had the inverter rebuild with expedited parts - again, the instructions that came with the rebuild kit were such that we were able to fix the inverter ourselves in a matter of a couple of hours.
We believe that the lighting struck ground, and back-fed into our system through the grounding rods - we found out that Outback actually markets a surge protector that mounts to their 'FX' series inverters to protect the equipment from lighting (surge) damage - protecting the AC, DC and generator in-and outputs of the inverter. Needless to say, after the April 2011 strike we add this little advertised part to our system.
IMPORTANT DISCLAIMER: While we did all the work on the renewable energy system on the farm ourselves, working with electricity is inherently dangerous - let alone, raising a 100' tower with a 1kW wind generator on top is not something that should be taken lightly. Making your own electricity from sun and wind is surely do-able, but please keep in mind your own skill set and comfort level, and consult with a licensed electrician when needed (which may also be a requirement based on local building and zoning regulations)