Smart Power Generation
Payback for these solutions is typically around three years, significantly better than for conventional systems, with site installation times and disruption
significantly reduced.
Small-scale combined heat and power is well recognised as a sustainable solution to CHP generation at an industrial facility. Electrical energy is generated by a reciprocating gas engine (similar to a diesel generator however the engine is powered by natural gas or biogas). Heat is generated by the system in two places: Low grade heat (circa 80°C) by the engine itself and higher grade heat (up to 200°C) by the exhaust. The combined efficiency of the system can be over 85% with up to 40% of the energy being delivered as high value electricity.
Unfortunately, the high cost of integration of CHP systems and finding use for the various grades of heat produced by them, often puts project paybacks periods to over 6 years.
After listening to clients who wanted to install CHP but found they had no use for the lower grade heat, and/or no distribution systems in place due to the existing factory being designed for steam, Nthalpy designed a steam only reciprocating CHP system.
At the heart of this new innovation is a high-temperature heat pump. Within the system, the heat pump used to boost the 80°C engine hot water to steam temperatures. This steam is then injected into the existing steam system at the required pressures and distributed utilising the existing steam pipework.
The integration costs of such an enhanced CHP system are significantly lower than conventional CHP systems, and utilising the high-temperature heat pumps we will ensure that 100% of the heat generated from the CHP is delivered to the factory as steam integrated directly into the site’s existing distribution systems.
Steam-only CHP solutions range from 100kW through to 2000kW. Typical payback periods will be are 3 to 4 years, including engine maintenance costs.
Application Examples
A facility has a requirement for 400kW of steam at 2Barg for a process cooking application together with 330kW of electricity to run pumps and fans. The load is required for 8000 hrs per year. Utilising a conventional steam boiler system and grid electricity the operating costs of the system is £340,000 per year.
By converting the system to an enhanced CHP solution, the operating costs drop considerably to £230,000, including annual maintenance. With an annual saving of £110,000 per annum and a solution cost approximately £400,000, payback would be in the region of 3.6 years. Payback excludes tax relief applicable to good quality CHP.
Energy cost used are £0.025 per kWh of gas and £0.09 per kWh of grid electricity.