It doesn't matter whether you're looking at renewable energy from the point of view of saving money or saving the environment: solar thermal systems are a great way to take your first steps. As it happens, preserving the environment and reducing your bills often go hand in hand, although it may not be immediately apparent when you look at the cost of installing new systems!

Renewable energy systems effectively cost you nothing. This is because they save money in the long run: their return on investment (ROI) may take years to reach 100% (i.e. when they've saved you as much as they cost) but it will happen eventually and - especially with rising fossil fuel costs – those savings will almost certainly accelerate in the future.

A solar thermal system is often considered first for many reasons. We'll put aside the environmental considerations for the moment (they deserve to be looked at separately) and just cover the financial and practical aspects:

• They are simpler to plan than complex options like PV arrays for generating electricity
• They are simpler to install and maintain
• They are cheaper than most other options
• The return on investment is higher
• They add value to your home
• They have a very long lifespan

A solar thermal system can offer 100% ROI in as little as three years, though most realistically reach that target in between five and ten years. That's pretty quick, especially when you consider that the system has a life of 30-40 years and adds value to your home on top of reducing the hot water bills! The collectors are even likely to outlast the roof they're installed on.

The lack of moving parts, easy maintenance, established technology and overall simplicity of solar thermal systems makes them almost a no-brainer as a first step into renewable energy. The only notable conflict is with photovoltaics (solar panels) as they both need roof space.