In its draft report on Electricity Networks and the Regulatory Frameworks the Productivity Commission encourages a standard approach to Embedded generation (12.2) and puts a focus on minor distributed generation such as PVs, VAWTs etc (13), and the disparities in tariffs. The general theme is to push toward time based pricing to assist technologies where it can be incorporated within a strategy of load lopping.
On 4 November CO2Land (www.co2land.org) posted “Balancing Energy in Your Business” and a quote from the story said “It might be time, if you have not already, consider curtailment opportunities, renewable generation, cogeneration or trigeneration (albeit some high profile projects may well prove to be an embarrassment for overblown claims), or combinations of technologies with emphasis on energy savings.” This sequel further explains the pros and cons of cogeneration and trigeneration. The message is fully understand it first!
Increasingly common, where gas connections are possible, is the embedding of co-generation and there is an increase trigeneration. A little 101 here:
- Cogeneration: Also known as combined heat and power, cogeneration uses wasted heat from gas-fired engines to project into other processes such as generating more electricity or producing heating.
- Trigeneration: Combined cooling, heat and power – goes a step further, simultaneously producing power, thermal energy and cooling. The cooling can be used for production processes or climate control.
Gas Today (www.gastoday.com.au/news/benefits_of_cogeneration_and_trigeneration/078333 ) ran a story on Benefits of cogeneration and trigeneration where the authors said: “Cogeneration and trigeneration are already well established in Australia, with a growing clientele of property owners and developers incorporating them into their new or existing buildings or plants. Flexibility in design makes these applications easy to adapt to different customer demands, and thus cogeneration and trigeneration plants can be found in various different locations, including:
- Urban areas with office buildings or retail complexes;
- Residential areas;
- Industrial or manufacturing facilities, such as breweries, abattoirs and dairies;
- Education facilities including universities and schools;
- Government sites such as state and federal agencies; and
- Data centres.”
However, with all good marketing efforts should come the balancing with ‘real’ stories. After reading a post of Dru Spork (Manager at Grocon in Sydney), he made the comment “those with experience should be able to chuckle along with this”, and what did he mean? Pitfalls we suspect and what to avoid when sizing. Some common mistakes and problems are:
- Design size for load lopping rather than operation. This can mean the unit is insufficient to handle the building load if isolated from grid connection.
- Total reliance on standards measures (AS3000) design ratings and not correctly sizing to match operation. That is not measuring correctly the actual equipment selections coupled with absorbed power/run power modelling.
- Not considering the ‘what if’ on the power requirements when other energy efficiency initiatives or technologies are introduced. Will there be a need to run the generator?
The economics are very important for the business case and overblown estimates could mean a stranded asset. Consider:
- The Capex investment for different load operations.
- Modelling the generator operation modeled at say 100%, 75% and 50% load (to predict available electrical load) and match this to absorber performance at 100%, 75% and 50% – rather than checking the quality of the heat output and how this works with the absorbers.
- Determine building heat load in the operational model.
- Be prepared for battles with the electrical authorities over fault levels and approval procedures (project approvals can take around 18 months).
- Empty buildings do not need power. The operations modelling of the generators assume occupation and operations of the building.
CO2Land org considers it is not uncommon that such projects fail and it tend to be because the introduction was not planned as well as it should have been. When talking to Ahmed Abdoh, he said “that is why we in Carbon Training International offer the only nationally recognised course in Cogeneration and Trigeneration that can help how to take the right decision on size and type. check out our course on www.co2ti.com . The primary material of the Course is the work of Winton Evers (Ecoprofit Management) and Ahmed Abdoh (CO2Planet) moderated by Bill McGhie (CO2Ti).
We also ask you to consider, you will get noise complaints from the adjacent buildings when operating, you will not get $120 per KWH value every day for generating, for these projects a ‘too analytical’ engineering report is a good report!