YouSustain

How To Go Solar Without A Huge Investment

by NeilT, 2010-06-08

Using solar technology is a daunting project for most people due to the perceived cost and expertise involved. But, you can leverage solar without needing to take your home off the grid. There are many ways to use solar for specific, smaller, purposes that can add convenience and portability. The uses here could range from bringing a small foldable panel along camping or hiking for charging electronics to installing one or two panels on your roof, or shed, to power specific appliances.

Choosing stationary or portable

Folding solar panel

Do you want power while mobile, or for a fixed location? For mobile use, folding or flexible solar panels are most convenient. There are also products specifically made for this, such as backpacks with panels on them. The most common use here is to provide power to recharge batteries in electronics. For example, recharging a camera, phone, music player or GPS unit while hiking or camping.


Solar panel

For fixed locations, a single and larger panel could be setup on a deck or installed on a shed or roof, for example. This could then be used to directly power devices such as a fan or garden water pump, charge device batteries directly, or charge a larger battery for general use. Once you have a battery, almost anything can be powered at any time of the day. As an example, complete outdoor deck/shed lighting units can be purchased that contain a panel, battery and light. The same principle can be be applied to almost any other device if you're setting up the panels and batteries yourself.

Some solid panels come with a convenient kick-stand, like the one pictured above. These give the benefits of the lower cost of solid panels plus the semi-portability. These could be setup on a deck or backyard, etc.

Choosing devices to power with solar

In order to decide what size of panels to purchase, you need to add up the maximum amount of electricity that will be consumed. The maximum will be the most devices you will want to operate/charge at the same time. Below is a table of the Watts consumed by some devices that may typically be powered by small solar setups.

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DeviceTypical Power Use
(Watts)
Notes
Mobile phone charger1-4Any kind, including smartphones.
Camera battery charger1-5All types
Small fan2-10Some are sold as clip-on units for cars
Music player charger4Typical USB charging
Portable stereo5Either a full unit or speakers connected to a music player
Small light2-13Ranging from small LED lights to a CF bulb
Medium electric cooler35Often described for use in cars
Small TV60Ranges drastically on the size, but this is the small end
Laptop85Less input power will help the battery last longer

For example, if you would like to charge a camera battery as well as run a small stereo, you may need to provide up to 10 Watts.

The next consideration is whether to provide power to the devices direct as 12V DC from the panels or converted to household AC. This will largely depend on the devices you have. It's easy to get 12V adapters for most electronics, often sold as a "car charger". AC power is typically provided by an inverter connected to a battery.

Choosing the equipment

Folding solar panels currently range from 5W and 6.5W units under $100 to 12W units around $200 and 25W units around $400.

Solid panels are about half the cost of folding units. 15W units cost around $100, 30W about $250 and 80W around $525.

Blue sky clouds

One thing to keep in mind when sizing panels for your power needs is that they often won't be outputting at peak levels during the day. Cloud cover will significantly reduce output, for example. A more powerful panel will provide more power during those off-peak times.

Batteries

If you want to provide power when there is no sun hitting the panels, you'll need batteries. This changes your setup so you're powering everything via the batteries and the panels are charging the batteries. There should be a charge controller between the panels and the batteries so you don't overcharge or leak power back through the panels. Thankfully, these days there are many products providing all this as a contained unit, so all you need to do is plug the panel into the battery and you're good to go. Often, an inverter will also be part of a combined power pack unit as well, providing AC power.