Michael and I got invited to Casparfest by a woman we had just met, and it was one of those “Hey, why not?” scenarios. We were camping, didn’t have any specific plans for the weekend, and happened to be only a few miles away at the time.
We arrived to find a free small scale solar power workshop and moseyed on in. The workshop speaker, Bruce Erickson, drew out some diagrams of possible photovoltaic system scenarios, showed us some cool gadgets, and inspired us to upgrade our little system.
Right now we have a portable 13 watt photovoltaic panel (about $80) which we’d like to upgrade to a 130 watt panel (over $800). The expansion is essentially to be able to power my office — a laptop computer for several hours a day and the inkjet printer once in a while. Otherwise our current PV panel would probably suffice.
Other upgrades:
- Charge controller that corresponds to the new solar panel
- True sine wave inverter
- Deep cycle battery
I put a donate button on the right sidebar if you’d like to contribute to our upgrade project.
{ 2 comments… read them below or add one }
I have been designing my solar system, and thought I’d pass along some things that I considered in designing my system.
Look up “Sunforce 39626 160 Watt Solar Back up Power Kit with Sharp Solar Modules” on the net, Amazon (and others…) carry it. This would give you 160 Watts, at a price in a similar ballpark to the $800 you are considering, plus give you 30 more watts. You might be able to cut costs a bit by using 2 60 watt panels, instead of the two 80 watt panels in the kit, this would give you similar power. One single panel will be more cost efficient, but is a bit less flexible, and doesn’t offer any redundancy.
In a 2 panel system, if one of the panels should go bad, you could still charge the system off the other remaining (good) panel. It might take a little longer to charge the battery up, but it’s better than not being able to charge up anything at all. If you have only 1 panel, and it goes bad (at $800 too!), or is damaged from some road debris, you could be out of power. Damaged panels probably won’t be covered by any warranty. Cheaper to replace one of the two smaller wattage panels, than to buy a single higher power panel.
It would also give you the flexibility to at some later point, put the two panels in series in a 24 volt system, and add another battery to double the system capabilities. power = voltage * current. So if you double the voltage, you double the power. Most of the higher powered systems (say 2000-4000 Watts) will be 24V, or even 48V systems.
The supplied charge controller in the kit is 12 V only though, a.f.a.i.k. Otherwise it seems to have good reviews on the net. It would probably need to be replaced though if you did go to a 24V system.
The supplied inverter in this kit doesn’t look all that interesting to me. I’m probably going with one of the ProSine units from Xantrex.
Sears makes a nice 100 amp hour, deep cycle, AGM marine type battery. It has 2 sets of terminals. 1 set of terminals can accept the incoming charge from the charge controller, and the other set of terminals can supply power the inverter. I used to have a Die Hard in one of my old VW’s, and it always started.
I plan to add a DC distribution box and fusing or breakers. Not picked anything out for this yet. Otherwise that’s pretty much the solar system that I am thinking about building.
I’m planning for very remote (snowed in in winter maybe even…), completely off the grid operation, so reliability and redundancy are my primary design goals.
Also hoping to put up an Air-X wind turbine. Probably will make one system (wind?) a 24V system, and the other a 12V (solar?) system. Use the 24V to do the clothes washing and handle the water pump. So a bit more redundancy is built into the overall system by having two completely separate systems. And I can segment the power into high and low power, based on power requirements, duration of use, and frequency of use.
Doing this really does make one think about where the power is being used though. I pretty much dumped any appliance that would use more than about 1500 watts in the process. Microwave, crock pot, etc…. all of that kind of stuff… gone!!
Not actually wired it all up, but that’s my plan.
—Phil
Hi Phil,
Thanks for your advice and insight! I’m still trying to learn some of the lingo so I can hold up my end of the conversation… but flexibility for travel and work are our primary concerns… backup and redundancy a little less so. Thanks again and I will take a look at the appliances you mentioned.