The Feed-In Tariff (FiT) came into operation in the UK in April last year, opening the door for the wider use of renewable energy sources within buildings, on roofs and in fields. The FiT provides a premium price for all energy generated, whether used or not, which is funded out of energy bills.

The concept of using photovoltaic (PV) systems to generate electrical power from solar energy has held a strong appeal for building services engineers for some years but their widespread use has been restricted by the return on investment. However green a building owner wants to be, there is invariably a payback element to the decision making, and a 20+ year payback will be rejected by the majority of financial directors.

Rainwater as a resource is mistrusted. It is something to get rid of as quickly as possible, hurried from roof and pavement into concrete pipes; suitable for gardens but not for domestic use.

In fact, research has shown that some rainwater, and even rainwater which has been stored in a tank, is as safe to drink as treated water provided through taps. More importantly, when rainwater is harvested it has the potential to significantly reduce the mains water needs of both domestic houses and commercial properties, lowering bills and putting less strain on drainage. It can also be used as a potential source of heating.

The government has set very ambitious targets to reduce emissions in the UK - an 80% reduction in greenhouse gas emissions by 2050 and an interim 34% reduction by 2020 - and the solar PV industry is extremely important in meeting these targets, which will require lots of low carbon energy.

Rainwater harvesting has become the next best thing when it comes to saving our valuable water supplies. Various techniques are available to make the collection of water possible for use within the home or commercial/public buildings. The pay off in terms of cost and water savings is clearly evidenced by those companies providing these techniques. However, when you look carefully at the projects where rainwater harvesting has been introduced it is rarely used beyond that which is necessary for running washing machines, flushing toilets and watering the garden.

Tackling climate change is a key challenge for all. The move to a virtually zero carbon electricity system will be essential if the UK is to achieve an 80% reduction in carbon emissions by 2050. Renewable energy, in particular, will play a vital role and the Energy Act of November 2008 sets out a series of provisions in order to help the government meet its targets.

Renewable technologies are often lumped together under a single heading, yet the requirements of solar, biomass and heat pumps could not actually be more different. Many system designs at present are overlooking the essential differences between these technologies and, as a result, are failing to optimise the cost and carbon savings that are available.