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There are many considerations for a designer when selecting energy sources for use in a product, including:

• portability of the power source
• environmental impact
• power output
• circuit/systems connections
• cost

Portability of power source

Technology advances mean many electronics products, from tablets to hearing aids, do not require a main power supply to operate them. Portable devices are powered by a battery that can be recharged as required.

Environmental impact

The impact from the production of energy can be classified as active or passive as no method of energy production is entirely clean.

Burning of fossil fuels to produce energy has an active impact on the environment as it releases greenhouse gases and other pollutants into the environment. The building of wind turbines to produce energy has a passive impact on the environment; it doesn’t produce any greenhouse gases but can produce noise pollution, which is an issue in built-up environments.

Power output

A designer will need to consider how reliable they need their power supplies to be, whilst also considering the impact that producing power has on the environment. The power output from power generators will vary depending on the source of the power. Renewable power plants produce an irregular output of power. For example, wind turbines rely on there being a constant supply of wind, which is dependent on weather conditions. Therefore weather conditions will dictate the amount of power outputted by a wind turbine.

Circuit/system connections

Electronic products will have a circuit within them; the circuit will require connecting to a power source. This power source will impact on the selection of how it is connected to the circuit.

Cost

The selection of a power source will play a role in the running cost of a product. A designer must make the correct choice regarding power, as an expensive running cost could have an impact on product sales.

Example

A designer is thinking of producing a kettle rated at 2,000 watts (W), which takes 150 seconds to boil water. Calculate the consumption of electricity in watts.

Convert 150 seconds into hours:

150 ÷ 60 = 2.5 minutes

2.5 ÷ 60 = 0.042 hours

Multiply this by the wattage:

0.042 × 2,000 = 84 watts (W)