A high-efficiency motor (HEM) is an electric motor than performs above mandatory minimum. New materials, better design, and better manufacturing have led to major improvements in motor efficiency overall.

Savings realised by using HEMs can quickly outweigh the purchase and installation costs because these modern motors cost less to run than conventional units. This means the purchase costs can be recuperated during its operational life.

When running at low load, electric motors are less efficient. A motor power optimiser (also known as load sensing optimisers) could save between 5 % and 15 % on electricity.

Motor optimisers are solid-state devices that automatically monitor the load on an electric motor. Under low load conditions, they reduce the voltage.

Flat belt drives are simple mechanisms that enable power from a rotational power source (e.g. electric motor or combustion engine) to be transferred to rotating machinery. Previously, flat belt drives had problems (especially with high tension and alignment). However, improved designs and advances in materials now mean that both low and high-power transmission is efficient using flat belt drives.

Compared to V-belt drives, flat belt drives are 2.5-3 % more efficient, and investment costs can be recouped in a few years. The advantages of using flat belt drives are:

VSDs prove that speed really is relative after all

Variable speed drives (VSDs) – also known as drive frequency converters, adjustable speed drives, or inverters – are an increasingly popular measurement and control system in industry.

VSDs can adjust electricity supply to an AC induction motor, automatically and accurately changing its speed and torque output to match real-time demand on the machine.

Result

Air source heat pumps… an absorbing proposition

Air source heat pumps absorb heat from the outside air. This heat can subsequently be used to warm radiators, air convectors and water, or in other heating systems. The process lowers fuel bills, cuts carbon emissions, and requires minimal maintenance.

The way it works is, ambient heat is absorbed at low temperatures into a fluid that passes through a compressor and generates higher-temperature heat, which is channelled through the heating circuit.

A great introduction to ground and water source heat pumps

Ground and water source heat pumps (GSHP) are easy to run once installed and provide low-carbon heating or cooling. Average reduction in CO2 emissions are reported to be from 25 % to 70%. These reductions depend on the use of GSHP - either for cooling, heating, or both. These systems offer the benefits of reduced running and maintenance costs, and overall energy bills, which offsets the up-front capital investment that is often higher than for conventional systems.

Insulating the pipework and valves of a hot-water and heating systems could help cut heat loss or heat gain by up to 90 %. In one or two years, the investment could be recovered, and savings made.

Take an office working on a single-shift system, for example. Fitting insulation to 100 mm pipework would cost around € 23 (£ 20) a metre but save € 23 (£ 20) a metre, assuming a gas price of € 0.03 (2.5 pence) per kWh. That means a payback period of just one year.

Biomass heating is a proven technology which most commonly uses virgin wood, certain energy crops, industrial wood residues and certain agricultural residues to produce heat. Biomass is considered a low-carbon technology if the feed material is derived from sustainable sources. Significant carbon and operational cost savings, as well as reduced fuel price volatility, are achieved with the use of biomass heating. Using certain biomass resources as fuels can also help divert by-products from landfilling and reduce costs associated with waste management.

Flash steam released from hot condensate can be recovered and applied elsewhere in the plant to maximise overall efficiency. Recovery systems reduce steam-raising costs, utility bills and CO2 emissions, and help achieve significant savings in fuel, water and feed-water chemicals. The return on investment is quick (around 3.4 years with the assumptions taken here). Jacketed vessels, flash-steam recovery vessels, and several other tools are available to operate flash steam recovery.

Some conditions need to be satisfied for successful flash-steam application:

The return of the condensate

Steam condensate is a well-known by-product of many industries. What is less well known is that it can be a powerful source of heat that can be reused.

Using this end-of-pipe steam to improve efficiency makes economic and environmental sense. A plant’s energy load and water consumption can also be cut by insulating pipework and preventing steam and condensate losses.

There are two main types of condensate recovery systems: