Renewable energy comes from sources that always renew themselves, so that energy can always be taken from them.  The main types of renewable energy resources are described below:

Solar photo-voltaic (PV)

The light from the Sun contains energy that can be collected and directly converted to electricity by solar cells in solar panels.

Solar thermal

The heat from the sun can be collected and used directly (as it is in a domestic solar hot-water system, or for space heating in a solar home) or it can be stored, and converted to electrical energy using a steam-turbine generator.

Wind

The energy in wind can be collected using a wind turbine which is connected to an alternator to make electrical energy.

Hydroelectric

The energy in moving water can be collected using a hydro-turbine which is connected to an alternator to make electrical energy.

Geothermal

The heat from the below the surface of the Earth can be collected and used directly (for instance, to produce hot-water for heating or domestic use, or for space heating) or it can be converted to electrical energy using a steam-turbine generator.

Cogeneration

Many industrial processes create waste heat.  This heat can be collected and used for other industrial purposes or it can be converted to electrical energy using a steam-turbine generator.

Biomass

Plant material can be burned to create heat.  The heat can be used directly, or it can be converted to electrical energy using a steam-turbine generator.  Plant material can also be fermented to produce gaseous or liquid hydrocarbons that can be used as fuel to run internal combustion engines or to generate electricity.

Tidal

The energy in water that is moving because of tidal flow can be collected using a hydro-turbine generator to make electrical energy.

Wave

The energy from the vertical movement of water waves can be collected by mechanisms connected to an alternator to make electrical energy.

Using renewable energy

Solar PV energy is the best form of renewable energy to use on a small scale at any location because it’s relatively cheap, scalable, reliable, low maintenance, long-lasting and sunlight is available anywhere. The characteristics of solar PV electricity, like most renewable energy sources, are mismatched to the way we use electricity in our homes.  Solar panels produce a steady supply of electricity over a long period of time, but when we use electricity in our homes we commonly use it at high power for a short period of time with long periods of very little use.  Solar panels also don’t help us at night when they don’t produce any energy. The best way to resolve this mismatch is to store the renewable energy as it is made, for use later when we need it, and to combine it with another always-available source of energy such as a diesel generator set.  When renewable energy is combined with energy storage and a supporting diesel generator set it becomes an effective and reliable hybrid independent energy solution. Eniquest’s PowerMaker Solar Diesel Hybrid Power Plant range of hybrid independent energy solutions incorporates renewable solar energy, energy storage and a supporting diesel generator set.