In general, panels are more efficient in cold weather and batteries are more efficient in warm weather. The longer summer days offset the efficiency issues in warm weather. Longer nights create issues for us having enough battery power stored up in the cold season.

Panels

We currently have 4 Kyocera 120 watt panels which produce 7.2 amps. We paid approximately $500 for each panel. The panels are installed in pairs on triangular wooden frames. We manually track the panels during days that we are home by moving the frames to face them towards the sun.

During the day most of our power usage is direct from our panels. The batteries are charged up during the day for use at night and on non-solar gain cloudy days.

Batteries

Batteries are the weak point in any solar system. They deteriorate with time and their efficiency is temperature sensitive, right up to not working at all if they freeze.

Our original battery bank is made up of eight Trojan 105 deep cycle 6 volt batteries that we paid appx $75 each for. They are hooked up in pairs to create a 12 volt system.

Jonathan currently maintains the batteries once a month which includes cleaning off the connectors and topping off the fluid. We look forward to eliminating this chore.

We are in the process of changing over to solid gel batteries as we can afford them. One of these bigger heavier batteries substitutes for 2 of the Trojan batteries. They do not require as much maintenance and are not disadvantaged by cold weather.

Gizmos

Our charger is an RV Power Product Solar Boost 50. It handles 50 amps and has 'powerpoint tracking' which distributes power across the batteries evenly increasing our incoming power by 30%. We can only add 2 more panels before we will need a bigger charger.

Our inverter is a ProSine 1000 True Sine Wave which we paid appx $700 for. We lost one inverter to a lighting strike during our first year out here, and the current inverter has a small issue with its on/off switch. Inverting power from DC to AC causes a 10% loss in power. Our goal is to be all DC powered and so we are switching things over to avoid being dependent on the expensive inverter component, and to eliminate the conversion power loss.

We only use portable computers which have a much lower power requirement than standard box CPUs and monitors. We are learning that many kitchen gizmos are available in DC power models but mostly we have learned how many electrically powered things we do not need. We run quite a few things, including a couple of small digital clocks, on rechargeable AA/AAA batteries and have a DC power battery charger.

After the computers, the biggest impact for people trying to get off the grid and into a low cost low power solution is in the Kitchen. We gave up our microwave and electric coffee maker. The electric waffle iron is in a box in storage, the food processor and breadmaker got sold. There are other ways to do these things. Wanna live off the grid? Get excited about slow food, it is better for you anyway.

CHANGES

Improving and refining our power situation is constantly on our minds and in our project box. Changing over to gel pack batteries, adding solar panels, moving from AC to DC powered items, and wiring the house for DC power lighting are all on the plan for the near future.

During the winter 2004-2005 we will relocate our solar panels to a sunnier area away from the dome where we won't lose any hours of sunlight to juniper bush shadows. The inverter and charger will move outside to the shed so that we do not have to listen to the inverter fan anymore. The batteries will move out from underneath the dome to the shed with the gizmos and we'll install our first two gel pack batteries.

As our solar plant expands we gain some options. SunDanzers are fabulous DC power refrigerators and freezers. We will add a freezer and change over from the propane fridge to a DC power one as soon as funds and power availability allow.