 Ten years ago, installing solar technology to produce energy in your home was the preserve of the eco-show-off or the wealthy and super-committed environmentalist. Things are different today. Rising energy prices, advances in technology and government legislation have all made the task of producing energy simpler and more cost-effective.  The technology behind solar energy is relatively simple. Solar electricity systems, also called photovoltaic (PV) systems, use solar panels made of interconnected silicon cells that convert energy from the sun into direct current (DC) power. The power is converted into alternating current (aC) power - the type we use in our homes - through an inverter. The system is wired into a household's existing electrical set-up and a meter records how much energy is being generated.  Solar water systems also use panels.  They contain a fluid that heats up throughout the day and is pumped, via insulated pipes, into a solar coil inside a hot water cylinder. The coil helps heat some or all of the water in the cylinder. On average, depending on the amount of water needed, a solar system could heat all of a household's water in summer and over a year could supply 30%-50% of its requirements.  "The technology behind solar energy has developed over the last 10 years," says Jaryn Bradford, a development manager at the Energy Savings Trust (EST). But he adds that the popularity of the technology is what has led to lower costs. "Solar photovoltaic cells are manufactured from silicon, so the cost of these are not going to suddenly come down. But what has changed are the economies of scale - installers are doing more business, so installation costs have come down. Small-scale renewables are becoming more mainstream."  He points to the government's feed-in tariff (see panel opposite), introduced nine months ago, as an important incentive. Since the tariff came into effect, inquiries to the EST on solar energy have doubled, he says. The scheme pays a fixed amount for the electricity you generate, so whether or not you use the energy, you can expect some return on your investment each year. additionally, if you produce a surplus of electricity you can sell it to the National Grid.  David Pitt, a senior product manager at anglian Home Improvements, agrees. "The feed-in tariff has made solar energy attractive," he says. "Until recently, you wouldn't get the returns you get with the feed-in tariffs. Not just at anglian but nationally, the interest in photovoltaics has been huge."  But the up-front costs of solar schemes are high. The EST says a typical solar PV system costs about ?12,000 to install. "It will take around 10-15 years to pay that back from the money you will receive from the feed-in tariff," says Bradford. "But before the feed-in tariff, it would have taken around 25 years, so that's a significant improvement."  So what do you get for ?12,000? Bradford is at pains to point out that although there is no such thing as an average family, a typical solar electricity system of about 2kWp (see panel) will generate 1,600-1,800kWh of electricity a year - enough for roughly a third of the household's needs.  anglian's estimates are more generous. It reckons that a typical scheme of 10 to 16 solar panels could generate 1,870kWh of energy a year, about half the amount an average household uses. This is worth ?722 in cash based on the feed-in tariff.  additionally, homeowners can sell kWhs they generate but do not use (in summer, perhaps) to the Grid and receive an extra 3p per unit. as Pitt points out, at this rate "it's more beneficial to use energy than sell it".  and of course solar panel owners will still have to buy from the Grid (average unit cost 13p) when not generating their own power, at night, for example, or when their needs outstrip their capacity. So if you're thinking of installing solar technology, ensure your home is energy-efficient to start with, advises Bradford. So as well as double glazing windows and insulating your home to the maximum, small things such as installing low-energy light bulbs, buying only the most energy efficient, a-rated appliances and never leaving them on stand-by will make a difference to your energy consumption. "It means you'll get even more benefit from microgeneration technology - and you'll make more money from having it installed," says Bradford.  In terms of whether this adds value to your home, the jury is out. Most people installing PV panels or solar water schemes do so because they intend to stay put. Nobody has yet shown such schemes increase house prices. But with the cold winter biting and energy costs rising, self-generated power is not to be sniffed at.  Green dream  Karl and Jane Godden moved with their two young daughters to Sloley, a hamlet about 12 miles north of Norwich, to pursue what Karl calls "the rural dream. We got into things like growing vegetables, recycling, composting and collecting rainwater."  They had already used an 