A beginners guide to solar power
First published June 2008, updated December 2011.
Is it illegal to love a solar panel? If so, I’ll gladly go to jail! It’s one of my favorite choices for green energy!
If you’re considering buying a solar power system but you’re confused about the choices available, this article is the first in a series I’ll be publishing over the coming weeks to explain the basics of solar energy related equipment, including solar hot water systems.
This initial guide will briefly outline the major components and types of systems, costs vs benefits with following articles looking more in depth at each aspect.
Solar power benefits
The benefits of a solar energy system are many:
- It generates renewable energy (electricity) from a natural resource – the sun
- It can be a cheaper way of getting electricity to a remote location
- No emissions are created from the electricity production of the panels
- Solar panels are durable. There’s no moving parts. Most panels come with a 25 year warranty and many that were installed in the 1970’s are still working fine today.
- Renewable energy rebates are now available in many countries around the world making the acquisition of a solar power system more affordable and the payback time much shorter.
- Very low maintenance
- Makes you more energy aware
- Increases the value of your property
Solar equipment production and pollution
Just on the topic of emissions and pollution; some solar power naysayers point out that the production of solar panels and equipment is energy intensive and this is totally true; but in in the case of solar panels, not only are the materials recyclable, but it can take as little as 12 months for energy payback; depending on the geographical location.
By this I mean the amount of energy that’s gone into making the panel will be produced by the solar module within a 12 month period. Given that solar panels have such a long life, taken over the long term, that’s a much smaller footprint than ongoing production of coal based electricity, even if it were produced by the so called “clean coal” technology – a term that’s somewhat of an oxymoron.
Even in battery based systems, again, the batteries can be recycled as can just about everything in a solar power setup. This differs greatly from coal fired energy generation where there is only pollution and greenhouse gases every step of the way.
How does solar power work?
A solar panel consists of an array of PV, aka photovoltaic (PV photo=light, voltaics=electricity), cells which consist of a positive and a negative wafer of silicon placed under a toughened layer of glass. When exposed to sunlight, the sun’s rays generates electron activity and wires connected to the photovoltaic cells capture these electrons – then when connected to a circuit, a DC electrical current is created which then travels down suitably sized DC wiring. Learn more about solar panels.
What happens next depends on the type of solar power system is being used.
Types of solar power systems
There’s two main types of configurations; SAPS (Stand Alone Power System) and mains grid connect.
Mains grid connect
Mains grid connect systems are those that are tied in with a standard mains power supply.
When energy is is being generated by the solar panels, a grid connect inverter converts that electricity from DC to 120v or 240v AC, which can then be used directly by standard electrical appliances. At night, your house draws energy from the grid per usual.
In a situation where the system produces more electricity than is immediately required, the extra is then fed back into the power grid and you can often get a credit from your utility on your next bill! It’s quite amazing to watch an electricity meter running backwards! Grid connect systems are relatively simple to set up and require next to no maintenance – usually just a wipe down of the panels once a year.
Learn more about grid connect solar power
Grid connect system
Image provided by Energy Matters – the solar power specialists
SAPS – Stand Alone Power System
A SAPS setup is isolated from the mains grid and uses a deep cycle battery bank to store the electricity. This is the type of system most often used in remote locations.
The electrical charge from the panel is piped through DC wiring to a solar regulator or charge controller; which is a small box that controls the amount of charge going into the batteries in order to prevent damage to the battery bank. DC appliances can then be run directly off the battery bank or an inverter added in order to convert from DC to AC; which can then be used by standard household appliances. The batteries used in a stand alone solar power system are specially designed for constant discharging and charging and if properly selected, will last for years – these are known as deep cycle batteries.
Both systems have their advantages and disadvantages, for example, in a grid connect setup, if the mains electricity supply suffers a blackout, that shuts down electricity generation of your own system too – so you’ll be without power unless you have a battery backup.
In a stand alone power system, while you’re totally independent, there is additional cost in the need for batteries, plus a little more monitoring involved – but looking after a SAPS system is by no means rocket science. I’m proof of that :).
Solar energy equipment is getting cheaper
Ever since I became aware of solar power as a young ‘un in the 70’s; the idea of creating electricity from the sun has fascinated me. Back then, you needed to be a millionaire to have the technology and these days it still isn’t dirt cheap; but prices are coming down and renewable energy rebates offered by many governments now puts solar power into the reach of many more people.
For people in remote areas it can be far cheaper to install solar power that access mains electricity. For example, the system I have for use on chunk ‘o dirt in the outback cost around $1600 back a few years ago and that gives me more than enough power to run my notebook for 14 hours a day plus some lighting. The costs of the same equipment have dropped nearly 50% since then.
In order to get mains electricity to the block would have cost me upwards of $20,000! My system is also fully mobile; at the end of each trip, I pack it all up which only takes a few minutes and bring it back to suburbia – so if we ever have a blackout here, I’m still able to work!
Sizing up a solar power system
The two most common questions in relation to solar power are:
“How big a system will I need and how much will that cost?”
Just to give you a general idea, at the time of writing, it will cost an average household anywhere from – brace yourself – $14,000 – $20,000 fully installed to gain all of their power directly via solar electricity and more for a stand alone system – but wait just a minute.
That’s incredibly pricey, but before you decide solar power is totally out of reach, there’s some things to consider that will *substantially* drop the cost. Those prices are also based on a 4 – 5 kilowatt system; meaning they’ll crank out 4 – 5 kilowatts per hour during peak sun hours; it’s a lot of juice!
Cutting down the costs of solar
Firstly, you don’t have to commit to buying enough solar panels to provide all your needs if you already have an alternate source of power such as mains. You can buy a smaller system, then build on it later as prices should continue to drop in the years ahead.
As mentioned, many governments also offer substantial renewable energy rebates that can reduce the costs of an entry-level solar power system to just a couple of thousand dollars.
One of the biggest ways you can cut down costs is to reduce the amount of electricity you use – and this is one of the wonderful things about solar power – it makes you very energy aware and that provides additional environmental benefits.
For example, let’s take a look at my computing needs. Previously I had a desktop computer and was running normal lighting – so some quick calculations:
Desktop: 200 watts x 14 hours = 2800 watts
Lighting: 75 watts x 14 hours = 1050 watts
Total: 3850 watts
Then after my switch to a notebook and CFL (Compact Fluorescent Lamp) lighting:
Notebook: 60 watts x 14 = 840 watts
Lighting: 5 watts x 14 = 70 watts
Total: 910 watts
.. and it was even less than that once I started using power saving features of the notebook and made a few other minor modifications to the way I work.
These two changes meant I needed much less than a third of the electricity I was using before and that translated to needing less equipment to generate the electricity – huge savings there, without sacrificing any sort of performance.
There’s so many ways we can cut power usage throughout the home without having to make major sacrifices! Based on that example, it should be quite doable for many households to cut down their own energy consumption up to half; therefore needing half the capacity in solar panels and associated equipment.
If you’re an independent sort of person who is concerned about the environment; the satisfaction you’ll feel from sitting back and looking at your solar panel system generating electricity quietly and without any emissions is really hard to describe. It’s empowering – that’s probably the best way I could sum it up. Knowing that the panel I have will still be cranking out amps in over 2 decades from now is also very reassuring.
While the costs can be little difficult to swallow, it’s important to remember that the era of cheap energy is now over – and while solar equipment is coming down in price, the cost of oil due to peak oil and the price of coal are rapidly escalating. At some stage in the future and likely not too far away, I believe we’ll see cost parity between fossil fuel generated energy and green power!
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