Renewable Overview

A brief overview of some renewable technologies are given below.

Solar PV

Solar PV is perhaps the best known renewable technology. It was actually first invented as early as 1860, since then the technology has come on leaps and bounds and the last 40 years, especially, have seen a dramatic decrease in the cost of solar PV at the same time as an increase in efficiencies causing them to become a cheap and reliable technology. The size of the system required depends on your needs and your building.

A typical household can meet all of their energy needs with a 3.5kw system (costing between £4000 – £6000) and with an average annual saving of around £800/year.

Solar Thermal

Solar water heating systems capture the heat from the Sun and use it to heat up water for use in the home.

A Typical system will cost around £3000, provides heating and hot water and can save around £300 per year


Wind turbines harness the power of the wind to turn a generator, a wind turbine’s output depends greatly on your location but for guidance A 1.5-kW wind turbine will meet the needs of a home requiring 300 kWh per month in a location with a 14 MPH annual average wind speed.

This size of system costs £1500 – £3000.

Heat Pumps

Heat pumps use energy in the ground to deliver heating and hot water. to the home. They work using gas expansion, similar to a fridge but takes advantage of this principle for heating rather than cooling.

As a rule of thumb, a ground-source system is likely to cost about £1000 per installed kilowatt (kW).

DIY Renewables

Disclaimer: Do it yourself carries with it with it inherent risks, this is especially true where electricity is involved. All DIY projects are purely at your own risk. As with any DIY project, unfamiliarity with the tools and processes can be dangerous. Information should be used as advice only.

That said, there are few things more satisfying than creating power with your own two hands. This is a guide to get you started on your DIY renewable journey, to give you the ability to build your own renewable technology.

Electrical safety – Electricity can be dangerous, we recommend reading the HSE (Health and Safety Executive) guidance here before dealing with electrical components.

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Understanding electricity

Common Solar PV Components

Common solar PV symbols

Basic circuit


Understanding electricity

Electricity is the presence and flow of electric charge. When we talk about circuits we are talking about the flow of electrons through conductors such as copper wires.

Ohms law:

Ohms law is one of the main tenets of circuitry and states that:

Voltage (V) = Current (I) x Resistance (R)

Where voltage is the electromotive force or potential difference expressed in volts.

Current is the flow of electricity

And Resistance is a measure of the difficulty to pass an electric current through that conductor.

Common Solar PV Components

Some of the basic components of solar PV circuits are:

TreeThinker diode Diode: A semiconductor device with two terminals, typically allowing the flow of current in one direction only

TreeThinker LEDs.jpg  LED  – Light emitting diode (small lamps)

TreeThinker Silicon.jpg  A semiconductor: A substance that has a conductivity between that of an insulator and that of most metals (silicon is pictured).

TreeThinker Battery.jpg  Battery: A container consisting of one or more cells, in which chemical energy is converted into electricity and used as a source of power.

TreeThinker Solar Cell.png  Solar cell: A device which converts solar radiation into electricity.

TreeThinker Resistor.jpg  A resistor: A two-terminal electrical component that implements electrical resistance as a circuit element.

Common solar PV symbols

In order to communicate the setup of electrical circuits, standard symbols are used, the following are those commonly used in solar PV circuits:

TreeThinker Solar PV Circuit Symbols

Basic circuit

A circuit is a complete and closed path around which a circulating electric current can flow. The most basic circuit uses a battery and an LED, a circuit diagram for this is shown below:

TreeThinker Basic Solar PV Circuit.gif


The components of the circuit are usually connected by wire, the connections need to be secure to insure the circuit works and to make the circuit safe.

TreeThinker Copper tape.jpgCopper tape – Copper tape is the simplest way to connect components in a circuit, it can be purchased in most hardware stores or garden centres and comes in a roll of sticky back metal, simply sticking two components together with the sticky side forms a connection.

TreeThinker SolderingSoldering – Soldering takes a little more effort but creates firmer and more efficient connections, solder is also a lot less expensive than copper tape. To solder, heat the metal of the component to be connected with the tip of the soldering iron for a few seconds, then apply the solder at the connection to the other component, the solder will melt to the components joining them together.

What is Passive Design?

Passive design takes advantage of clever design and the natural environment to make the most of the heat available to your home. Passive design incorporates many features such as glazing and orientation and can greatly reduce or even eliminate the need for a heating system.

Solar Insolation

Solar insolation is the use of natural sunlight to heat the home, it can be surprisingly effective and good window design could create a net benefit of around 4 – 8kW of energy (The equivalent of 2 to 3 hours of cemtral heating).


The way the building is oriented can greatly influence the heating effect of the sun and the cooling effect of breezes. Orientating a building East – West reduces the need for heating by around 10% on average. Additionally, orientation can ensure maximum gains for solar PV and solar thermal systems.

Sealing your building
Air leaking is responsible for roughly 15 – 25% of heat loss in the home during winter. Properly sealing your home is one of the simplest actions you can take to save heat and has a dramatic effect on your bills. The colder the weather the more you benefit as air flow between inside and out is reduced.

Passive design can be free if you are planning new build and simply requires changes to your existing plans, however modifications can be expensive in existing buildings. To find out more get in touch.