What We Do
Carbon Zero Consulting applies its experience and expertise in identifying and implementing down-to-earth, pragmatic solutions.
Although our primary area of expertise is in the field of GSHC, we also have a very high level of in-house and associate expertise in the following areas:
- Air source heating
- Biomass heating and power
- Solar hot water and photovoltaic power
- Wind power
- Micro-hydroelectric
- Waste to energy
We are also very active in the provision of training and professional short courses. These include a bi-annual intensive one-day seminar on GSHC technology and ‘train the trainer’ days for heat pump suppliers and installers. We also provide all in-house training on GSHC for the Environment Agency.
BACK TO TOP
GROUND SOURCE HEATING AND COOLING
Ground source heating and cooling (GSHC) involves the recovery of energy as low grade heat from the ground or the disposal of heat from a building into the ground, usually utilising a heat pump.
In the UK the temperature of the soil and upper few metres of rock are at a remarkably constant temperature, equal to the average annual air temperature. For example in southern England this average is about 12°C and in northern Scotland the average is about 9°C. The sun provides the majority of this heat energy with only a very small amount coming from the Earth’s interior. This is why the technology is termed "Ground Source" and not Geothermal Energy.
There are two basic systems to provide a ‘ground-source’ for a GSHC system:
Closed Loop
Heat is absorbed from the ground via plastic pipes filled with a carrier fluid. The pipes can be installed horizontally in trenches, in boreholes or in a lake. The length of pipe required to provide sufficient ‘ground-source’ depends on the building’s seasonal heating/cooling characteristics and the properties of the rock.
Open Loop
In areas of suitable geology, water is pumped from a borehole to a heat pump or heat exchanger. Thermal energy is extracted from the water within the heat pump cycle. The resulting cooled water is then re-injected to the ground or disposed-of to the environment.
For both closed and open loop systems there is the option to provide cooling as well or instead of heating. GSHC systems can be designed to provide heating for a small house of say a few kilowatts (kW), up to very large commercial buildings requiring many megawatts (MW) of heat and cool.
The fundamental science behind heat transport in the ground, is directly analogous to groundwater flow. In fact commonly used groundwater analysis is based on heat flow theory. The assessment of risks associated with GSHC is therefore an extension of hydrogeology. This extension is often referred to as "Thermogeology".
Carbon Zero Consulting has specific, unrivalled expertise in thermogeology in the UK, and has been instrumental in its development with detailed involvement in many of the UK's largest and most successful systems.
Together with specialist associates, CZC is able to provide support to your GSHC project from concept development, risk assessment to project management, installation and regulatory permitting.
How A Heat Pump Works
Although the term 'heat pump' may be unfamiliar, anyone who has a refrigerator or an air conditioner has witnessed the operation of a heat pump, In the same way as a water pump moves water from a low level to a high level, a heat pump 'moves' heat from a low-temperature external source to a high-temperature interior space (e.g. your house).
The process of elevating low-temperature heat to 35°C or higher involves a cycle of evaporation, compression, condensation and expansion. A refrigerant is used as the heat-transfer medium that circulates within the heat pump.
- The cycle starts as the cold, liquid refrigerant passes through a heat exchanger (evaporator) and absorbs heat from the low-temperature source (liquid from the ground loop). The refrigerant evaporates into a gas as heat is absorbed.
- The gaseous refrigerant then passes through a compressor where the refrigerant is pressurised, raising its temperature
- The hot gas then circulates through a second heat exchanger (condensor) where heat is removed and pumped into the building at up to 55°C, although 35 - 40°C is sufficient for underfloor heating applications.
- When it loses the heat, the refrigerant changes back to a liquid. The liquid is cooled as it passes through an expansion valve and begins the process again.
BACK TO TOP
AIR SOURCE HEATING
In the same way as Ground Source heat pumps absorb energy from the ground, Air source heat pumps (ASHP) absorb heat from the outside air. Air-to-water systems produce hot water, which is circulated within a building through radiators or, preferably, an underfloor system.
ASHP systems can at times be prefered to ground source heat pumps due to lower capital cost and no requirement for an area of ground for trench or borehole excavation, As such ASHP technology is often more suited to smaller urban homes and retrofitting. They are typically a little less efficient in terms of running costs compared to ground source. DECC has yet to make a final announcement regarding ASHP technologies and the payment of RHI tariifs.
BACK TO TOP
BIOMASS HEATING AND POWER
There are various methods used to generate heat from biomass. The systems fall under the categories of direct combustion, gasification and combined heat & power (CHP), Common fuels include wood pellet, wood chip, logs and (less commonly) Miscanthus and straw.
Before oil and gas was burned in significant quantities, biomass in the form of wood fuel provided most of humanity's heating, as well as providing our first renewable energy resource - theres nothing new under the sun!.
After 25 years of cheap oil and gas - the UK is no longer self sufficient and is now exposed to the global fuel market. Recent massive price increases have in turn increased awareness and value of biomass for heat generation.
Biomass boilers offer an alternative to Heat Pumps and can be more suited to heating systems with radiators or homes with higher heat loss. A Biomass boiler produces hot water at the same temperature as a gas or oil boiler - and so can be used as a straight 'swap'. Biomass now attracts RHI tariff payments for commercial and district heating schemes. The domestic RHI is due to commence later in 2012.Photovoltaic and Solar Thermal
Solar PV (photovoltaic) uses energy from the sun to create electricity. PV requires only daylight, not direct sunlight to generate electricity and so can still generate some power on a cloudy day. The PV cell consists of one or two layers of a semi conducting material, usually silicon. When light shines on the cell, it creates an electric field across the layers causing electricity to flow. The greater the intensity of the light, the greater the flow of electricity. PV cells are referred to in terms of the amount of energy they generate in full sunlight, known as kilowatt peak or kWp.
In the UK an installation of 1kWp will produce 800-900 kWh (kilowatt hours) of electricity per annum, provided it is mounted in the right direction and aspect!. For the average domestic system, costs can be around £9,000 for a 4kWp system,.
Most systems are linked directly to the grid, Despite some recent interference by the government, the Feed In Tariff (FIT) system provides an excellent return for investment in PV.
Although the PV tariiff for a large domestic system of up to 4kWp is to be reduced to 21p (from 43p), there is still a return on investment of about 10% to be made - because PV panel costs have come down so much in the last 2 years.Solar thermal technology can provide 50 to 70 per cent of a home or business's hot water requirements. There are a number of technologies to choose from and can in many circumstances be integrated with a ground/air source heat pump system to provide all you domestic hot water needs. The Renewable Heat Incentive (RHI) was intoduced for commercial and multi-residence systems in 2011. The RHI for Domestic systems is due to commence late in 2012. Keep looking at our Latest News section for - well, latest news!.
BACK TO TOP
WIND POWER
Wind power is now the world’s fastest growing energy source and the UK has the largest wind resource in Europe. Modern wind turbines are operational for 70-85% of the time and over the course of the year, they will generate, on average, up to 35% of their theoretical maximum output. This is known as a load or capacity factor. The exact figure is dependent on the location, technology, size, turbine reliability and wind conditions. A modern turbine has a life span of 20 years or more.
We provide advice on the feasibility, design and cost for supplying wind-derived electricity to properties such as private houses, farms and offices. After identifying a good windy site, the second most important ingredient for a successful wind turbine installation is obtaining planning consent. We can provide support through this process.
The power produced by onshore wind farms is one of the cheapest forms of renewable energy available today, with continuing technological advances to bring the costs down still further.The introduction of Feed in Tariffs has made this technology highly attractive..
BACK TO TOP
MICRO HYDROELECTRIC
Carbon Zero Consulting can also provide input to deliver small hydro schemes. Small-scale hydropower is one of the most cost-effective and reliable energy technologies to be considered for providing renewable power generation. We have worked with water and water regulation for a very long time and so are perfectly placed to help you with planning and obtaining the regulatory consent needed to operate a hydro scheme.
In particular, the key advantages that small hydro has over wind, wave and solar power are:
- A high efficiency (70 - 90%), by far the best of all energy technologies.
- A high capacity factor (typically >50%), compared with about 10% for solar and a little over 30% for wind.
- A high level of predictability, varying with annual rainfall patterns.
- Slow rate of change; the output power varies only gradually from day to day (not from minute to minute).
- It is a long-lasting and robust technology; systems can readily be engineered to last for 50 years or more.
It is also environmentally benign. Small hydro schemes do not have the same kinds of adverse effect on the local environment as large-scale hydro.
Carbon Zero Consulting, together with expert associates are able to evaluate the best technical and financial options for power generation.
The introduction of Feed-in Tariffs for micro hydro schemes has made this technology even more attractive.
BACK TO TOP
WASTE TO ENERGY
Carbon Zero Consulting can advise you on many alternative forms of energy including transforming waste to energy.
BACK TO TOP
