Solar Power for Beginners
Trying to work out what exactly you need for a solar power system can be daunting. People may end up spending a small fortune and still not have the power they feel they need. I’m very grateful to a man called Klaus who visited my earthbag home this winter. In less than half-an hour he plied me with enough information to enable me to design a solar system tailor-made to my needs.
You don’t need to invest vast amounts of cash if you don’t have it. But you do need some stats. The trouble is information on small off-grid solar systems is curiously hard to find, or at the very least tricky to unravel.
Here I've cobbled together an idiot's guide to small, cheap solar systems in an attempt to shed some light on the strangely nebular science of solar power.
You don’t need to invest vast amounts of cash if you don’t have it. But you do need some stats. The trouble is information on small off-grid solar systems is curiously hard to find, or at the very least tricky to unravel.
Here I've cobbled together an idiot's guide to small, cheap solar systems in an attempt to shed some light on the strangely nebular science of solar power.
Basic Solar Power Equipment
There are four main parts to your solar system:
Controller (top left), inverter (middle), battery (bottom), fuse box (right)
1.Solar panels. These draw in the sun’s energy for you. The more efficient your panel, the more energy they absorb.
The two main types of solar panel are Monocrystalline (black) or Polycrystalline (blue/dark blue). There is still much confabulation about which is better and you can follow that debate here if you like. The truth is the manufacturer is more important than mono or poly.
2. Batteries. These store the power collected by the panels. The more you store, the more you can use when there’s no sun.
Again you are faced with a choice. Lead acid? Gel? Lithium? You can use any of these in your solar system though lithium are the best, but also the most expensive. Read about the pros and cons of each here if you are so disposed. Just make sure you're using deep cycle batteries, not car batteries.
3. Regulator (controller). This is the brain of your system. If your batteries over-charge or over-drain, their longevity is severely reduced. The regulator controls how much your batteries can charge. When they reach their optimum limit (preferably about 14 V) the regulator stops power coming in from the panels.
4. Inverter. Batteries pump out power at 12V. The inverter converts the 12V into a voltage suitable for your house-hold appliances (usually 220V or thereabouts).
The two main types of solar panel are Monocrystalline (black) or Polycrystalline (blue/dark blue). There is still much confabulation about which is better and you can follow that debate here if you like. The truth is the manufacturer is more important than mono or poly.
2. Batteries. These store the power collected by the panels. The more you store, the more you can use when there’s no sun.
Again you are faced with a choice. Lead acid? Gel? Lithium? You can use any of these in your solar system though lithium are the best, but also the most expensive. Read about the pros and cons of each here if you are so disposed. Just make sure you're using deep cycle batteries, not car batteries.
3. Regulator (controller). This is the brain of your system. If your batteries over-charge or over-drain, their longevity is severely reduced. The regulator controls how much your batteries can charge. When they reach their optimum limit (preferably about 14 V) the regulator stops power coming in from the panels.
4. Inverter. Batteries pump out power at 12V. The inverter converts the 12V into a voltage suitable for your house-hold appliances (usually 220V or thereabouts).
Watt? You Don't Know an Amp from a Volt?
So you've got your basic solar power equipment. All well and good. However, trouble brews when you want to use appliances that need more power than your system can handle. This is where you a cursory amount of electrical knowledge goes a long way.
Volts = Electricity’s equivalent to water pressure. The higher the voltage the more electrical current flows.
Amps (current) = Electrical flow rate
Watts = Units electrical power is measured in.
Voltage multiplied by amps = Watts.
In my mud home in Turkey, I used a small inexpensive system (cost a little over 1000 sterling back in 2012) with two 160 watt solar panels, two 200 AH batteries, a 600 watt inverter and a 20 amp regulator. But what does that mean?
1. I can’t use any appliance, or group of appliances that are over 600 watts. The inverter can’t handle it (actually better to stay below about 300 watts).
2. I can’t use any appliance, or group of appliances that burn more than 20 amps. The regulator can’t handle it.
3.There is a finite amount of power stored in the batteries. For the health of the batteries the system functions between 10.5 and 14.5 amps. That means I have 4.5 amps to play with when the panels aren’t sucking in light. So . . . at night time or after prolonged periods of rain the batteries will begin to run down.
Basically, appliances of less than 50 watts are what I look to use. As a general rule, small motors and battery chargers get the green light. However, anything that heats is a power-eater. I've already given away my toaster.
Volts = Electricity’s equivalent to water pressure. The higher the voltage the more electrical current flows.
Amps (current) = Electrical flow rate
Watts = Units electrical power is measured in.
Voltage multiplied by amps = Watts.
In my mud home in Turkey, I used a small inexpensive system (cost a little over 1000 sterling back in 2012) with two 160 watt solar panels, two 200 AH batteries, a 600 watt inverter and a 20 amp regulator. But what does that mean?
1. I can’t use any appliance, or group of appliances that are over 600 watts. The inverter can’t handle it (actually better to stay below about 300 watts).
2. I can’t use any appliance, or group of appliances that burn more than 20 amps. The regulator can’t handle it.
3.There is a finite amount of power stored in the batteries. For the health of the batteries the system functions between 10.5 and 14.5 amps. That means I have 4.5 amps to play with when the panels aren’t sucking in light. So . . . at night time or after prolonged periods of rain the batteries will begin to run down.
Basically, appliances of less than 50 watts are what I look to use. As a general rule, small motors and battery chargers get the green light. However, anything that heats is a power-eater. I've already given away my toaster.
What I can potentially use:
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What I can't use:
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Wavy hair and waffleless breakfasts are two of the sacrifices you'll have to make if you run a small 12V solar system.
Is a small system worth it?
In conclusion, for people off the grid with not much spare cash, the two-panel, two-battery option is a great solution to simple power issues like lights and laptop charging. Later, if you really can’t do without your cappuccino machine, either your system can be upgraded. But you might want to read about 24 volt systems if that's your plan.
