Combined Heat and Power Systems Engineering
Ricardo is a leading provider of technology, product innovation, engineering solutions and strategic consulting to the world's automotive, transport and energy industries. We have experience working on many of the CHP technologies – Fuel Cells, Sterling Engines, Organic Rankine cycles, Internal combustion engines and Linear Free piston engines. We have complete strategic and engineering capabilities to take a concept all the way through to commercialisation.
Combined Heat and Power Overview
Why combined heat and Power - CHP?
A conventional oil/coal/gas fired power station will run at an efficiency of 35%-50% the remainder is released as heat energy – power stations where possible try and off load the excess heat produced during generation. Ideally this is in the form of a district heating system or in some cases the heating of local greenhouses. However power stations are often built on the out skirts of towns and the logistics in piping excess heat is not cost effective.. The remaining heat is simply sent up the chimneys and escapes to atmosphere.
If the means of electrical generation can be localised on an individual household basis there is a greater potential to use the waste heat to the benefit of the home owner. This will not only reduce overall CO2 emissions but also reduce the overall fuel bill of households. Systems are typically powered by natural gas but other forms of fuels can be used such as bio gas and diesel. When this fuel is sourced from a renewable source then the environmental gas is even more compelling.
What is needed?
The typical average household needs between 1-2 kW of electrical power per hour. This power is not needed on a continuous smooth load but over an averaged 24 hour period. Any peak loading can be met by the grid and indeed any excess power can be re-fed to the grid. Although electricity grids are theoretically two way ie power can be pushed either way, there are a number of practical infrastructure limitations at the local end that limit the amount of power that can be re-fed into the grid. Before large scale adoption is can be achieved there will need to be an improvement of the local grid infrastructure.
Market situation
16,000 units were sold worldwide in 2005, with a total market value of €135,000,000. The Japanese manufacturers currently accounts for over 75% of the market (by unit sales) with the 5 biggest manufacturers being SenerTec (owned by Baxi), PowerPlus Technology (owned by Vaillant), Honda, Whispertech and Yanmar. The biggest of which, Honda, sold approximately 12000 units in 2005.
Currently in the UK there are an estimated 1,000 installed micro CHP units; these tend mostly to be of the larger internal combustion engine type producing between 3-10 KW of electricity per hour. When compared to the estimated number of installed primary domestic heating system – 15 million in the UK with an annual new installation of 1.5 million then the attractiveness of the market can be seen. If all new heating appliances installed had a form of micro CHP then annually this would be equivalent to building a large power station 1.5GW capacity (assuming full load) in the UK. Assuming optimistic uptake of micro CHP this could lead to a 5% reduction In CO2 emissions by 2030
| Technology |
Electrical to heat ratio |
Advantages |
Issues Faced |
| Fuel Cells |
40-50% |
Best potential electricity to power ratio |
Durability, cost of manufacture |
| Stirling Engines |
30-40% |
Mature technology |
Precision technology required in the manufacture of engines |
| Organic Rankin Cycles (reverse refrigeration cycle) |
25-35% |
Potential cheap route |
Regassing of secondary working fluid |
| Internal Combustion Engines |
30-35% |
Potential cheap supplier base |
Power electrical to heat performance |
| Linear Free Piston Engines |
20% |
Simple design |
|
Correct choice of system
Each of the above systems have different heat output when nominally generating 1 kW power. In order to achieve economic success this heat must be used in such a way to displace heat that would be otherwise used. A micro CHP system is said to ‘heat lead’ – when there is no need for heat then the cost of electricity production will not be competitive with that supplied by the grid.
Hurdles to adoption
There are a number of potential hurdles to overcome for all of the systems with the major ones being listed
- Cost of production
- Durability (10 year life cycle)
- High potential maintenance when compared to current simple boiler heating system
- Noise
- Initial cost of ownership
Sponsorship
Micro CHP has the potential to greatly reduce global CO2 emissions. It also has the potential to shift the balance between electricity and natural gas. As such the natural gas companies/utility companies are keen to sponsor Micro CHP technology. Governmental organisation are also keen to promote Micro CHP (through financial incentives ie Renewable Obligation, Zero Carbon buildings, direct grants etc) in order to help them achieve their CO2 reduction targets
Ricardo support
We have experience working with many CHP technologies:
- Fuel Cells,
- Sterling Engines,
- Organic Rankine cycles,
- Internal combustion engines
- Linear Free piston engines
Ricardo has complete strategic and engineering capabilities to take a concept all the way through to commercialisation.
We have specific capabilities in:
- Thermal efficiency calculations from first principles to fluid analysis and modelling.
- Control Strategies
- System and Community modelling of individual units
- Bill Of Materials
- Cost down processes
- Noise Vibration and Harshness – Analysis and Testing
- Prototype Manufacture
- Production drawings
For further information on micro CHP technology please feel free to contact us