CCHP & Distributed Generation

CCHP & Distributed Generation

Distributed Power Solutions (Onsite Generation)

Nowadays, distributed energy technologies are playing a key role in transforming the way we generate energy. This transformation is well-documented in Europe, but it is also happening elsewhere (the US, Asia & Middle East, etc.). Energiring can help to determine whether on-site renewable/conventional energy generation makes sense for clients’ business.

 

Energiring offers its customers a wide variety of local generation solutions ranging from renewable resources driven to gas-fired energy resource technologies for commercial (schools, shopping centers, hotels, swimming pools, airports, hospitals, etc.) and multi-family buildings as well as industrial applications. In the end of the day, end-users become partners sharing responsibility for more green energy supply in this way. Lastly, we do commercialization for distributed generation (DG)-related technologies developed by our staff, partners, and customers.



What is CCHP?

In a power station, only part of the primary energy input is used for power generation. The heat which occurs at the same time is generally discharged to the atmosphere without being used. According to literatures, only roughly 36% of the energy used in conventional large power stations is available as electricity which can be used. The rest is lost as waste heat or during transport. The heat needed by the consumer must be produced separately using a boiler. Much higher efficiencies can be achieved if the electricity is generated directly at the point of use, that is to say where the end consumer uses it, and the heat occurring is also used for producing space heat and hot water. Thus losses can be minimized compared with the separate generation of power and heat and consumption of primary energy can be significantly reduced.

Combined cooling, heating and power (CCHP) is the generation of electricity and useful heat from the same item of plant. In most CCHP installations, the electricity would be bought from the local supply network, and the heat recovered from the engine supplements or in some cases replaces heat from the sites boilers. CCHP systems can also provide cooling through the use of absorption chillers that utilize heat as their energy source.

There are several types of technologies to be used in a CCHP system: from fuel cell driven to Stirling based (external combustion engine) ones. Conventional CCHP systems, however, use a reciprocating piston or internal combustion engine (ICE- the same type as you could find in van or lorry), fueled by gas, to spin a generator thus producing electricity. The heat from the engine water cooling and exhaust are then used to produce hot water, via heat exchangers. Energiring supplies a range of traditional ICE-based CCHP packages.

The microturbine-based CCHP package differs from traditional CCHP because the engine is a gas turbine rather than a piston engine. The technology uses a gas combustion process to propel a turbine at very high speed. This turbine then rotates a permanent magnet generator which produces electricity. The hot gases from the combustion process then pass through a water filled heat exchanger which produces hot water (to be used later for direct heating and/or cooling purposes).



Why CCHP?

The benefits of CCHP when compared to importing electricity and using boilers to generate heat include (but not limited to):

  • Savings on total energy costs for the end-user,
  • Improved efficiency of fuel use (better fuel utilization factor),
  • Reduced emissions,
  • Independence and security of power supply, and
  • Exemption from the Climate Change Levy for energy costs.

The Iranian Government is committed to increasing the country's CCHP capacity and it forms a key element of its strategy to improve network reliability and increase fuel efficiency as well as to reduce the country greenhouse gas emissions. It is widely predicted that further legislation and incentives will be introduced in the near future to encourage the use of CCHP.



Which CCHP?

The key to the success of a CCHP system is getting the sizing right. Many CCHP installations are oversized because the facilities energy demand profile has not been assessed properly. 

To get the full benefits of CCHP, the unit needs to operate to its full potential, and all the power and heat produced has to be fully utilized. Hence, in assessing whether CCHP is appropriate for a building or development, it is essential that the electricity and heat demand profiles are established. It is common for annual electricity and gas meter data to be used to calculate average power and heating/cooling demand. This type of calculation makes no allowance for seasonal variations in demand, particularly heat. 

Electricity usage profiles can be obtained by looking at half hour meter data, which can be requested from your electricity supplier. Heat usage profiles are more difficult to assess. Monthly gas bill readings can be used to assess daily and hourly usage. Clearly there is a degree of inaccuracy in using monthly data to derive hourly figures, but it's much better then starting with annual data! 

Once demand profiles have been established, it is then possible to calculate the respective electricity and heat baseloads for the specific case; the baseload is the minimum hourly usage. You then size your CCHP unit based upon the appropriate baseload. In many instances, if the assessment process is done properly, the size of the appropriate CCHP unit will be much smaller than anticipated. In some cases, it will not be viable. 

The output from a CCHP unit is typically approx. 30-40% electricity, 60-70% heat, so you need to establish whether the CCHP sizing is electricity or heat led. For example, if you had an electrical baseload of 100 kW, a unit of this size would provide about 150 kW of heat. Hence, if your heat demand baseload is 150 kW or above, the CCHP size would be electrically led. However, if the heat baseload is below 150 kW, it would heat led (i.e. you would choose unit based upon the thermal demand). 

Note that it may not be normal to run CCHP during the night time period. This is because, over this period, electricity is much cheaper than its price during the day, and maybe it is not economically attractive to produce your own power. Hence, CCHP is usually assessed and operated for 15-20 hours/day. All of these require a precise study and reliable case-depended analysis which can be done by Energiring.  



Economic Viability of CCHP

The economic viability of CCHP is, first and foremost, dependent upon the unit size being appropriate for the facility. It is essential that all of the electricity and all of the heat from the CCHP package is fully utilized for the vast majority of the time. The cost benefits achieved by CCHP unit are a function of:

  • Electricity savings; power produced that would otherwise have been imported from the grid
  • Heat savings; heat generated that would otherwise have been using onsite gas fired boilers

Set against the benefits, the costs that need to be taken into account in assessing the economic viability of CCHP encompass:

  • Installation costs
  • Costs of fuel input required
  • Maintenance costs

The costs of CCHP, in terms of $/kW installed, reduce as the size of the unit increases. The same applies to the cost of maintenance. In addition, the larger the unit, generally the better the efficiency but lower reliability.

Although clearly every potential CCHP scheme needs to be assessed individually, typical simple payback periods for an appropriately sized CCHP installation are typically 4 to 6 years.

Contact Energiring for more information and/or any techno-economy questions regarding your own needs and case of application.

 

With a power rating of up to 500 kWe, small-CCHP systems cover electricity, heating, cooling and hot water demand for many industrial and commercial as well as residential applications. They can replace conventional space-heating systems in addition to dependence of national electricity grid to have more reliable, affordable, and secure source of energy. To reach this purpose, Energiring proposes a microturbine technology: AE-T100 CHP system.



AE-T100 microturbine driven small scale CHP technology

The Turbec Microturbine Company was originally a jointly owned subsidiary of Volvo and ABB and is now owned by an Italian technology manufacturer (Ansaldo Energia, AE). The AE-T100 microturbine is well proven with over 500 sets now operational worldwide. At full output, the unit produces 100 kW of electricity, 170 kW of heat.

The AE-T100 CHP unit is available in three different fuel versions: natural gas (AE-T100NG), biogas (AE-T100B) and external combustion (AE-T100E based on EFGT technology). The AE-T100 microturbine produces electricity and heat fueled by natural gas and achieves an overall efficiency of 90%. Exhaust emissions from microturbine of important headline polluting gases such as CO and NOX are an order of magnitude lower than emissions from reciprocating engines. In fact, the exhaust gases are so clean that they can be used directly in greenhouses to increase CO2 levels which promotes plant growth.

Micro gas turbines offer many advantages over conventional reciprocating gas or diesel engines. With only one moving part, they are inherently more reliable and maintenance costs are much lower than for reciprocating engines. Because the heat exchanger on the AE-T100 does not form part of the engine cooling system, unlike reciprocating engine CHP, the unit is extremely flexible with regards to higher water temperatures. They are also quieter, smaller and cleaner.

 A Business Case:
Energiring, as distributer/agent of Ansaldo Energia for its micro turbines in Middle-East, supports clients in terms of procurement, installation, commissioning, operation, and maintenance of this technology. We are going to start with this specific small-scale CHP technology across the Iran in high-rises, shopping centers, schools, hospitals, hotels, housing developments, cottage complexes, factories, greenhouses, cow farms, sewage treatment works, landfill sites, and island application.

In this regard, we make available a first class and tailored to the customers’ individual requirements maintenance and after-sale service alongside this product, and fully comprehensive operation and maintenance contracts are available for any equipment we supply and/or install. We offer fully comprehensive Maintenance Contracts for any equipment which we install and/or supply. Energiring also provides R&D ideas, contributes to research activities, and cooperates in proposal development within the research institutes which would be our clients for this well-established and famous CHP system. Please have a look at this summary

As Energiring only offers a refreshingly honest approach when assessing a projects technical and economic viability, if this technology/product that we supply isn't right for you, we will tell you; we'll even point you in the right direction if we think that there is something else available that is a better solution for your application, be sure!

If your objective is to install CCHP, of whatever form and fuel type, which will stand the test of time and meet payback expectations, then we have a solution that is right for you. Nevertheless, if you are installing CCHP to fulfil a planning requirement and/or your sole driver is capital cost with no consideration of long term operating charges and/or efficiency, then you need to look elsewhere!