Untangling the Complexity of On-site Electricity Generation
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The document provides an overview of on-site generation, including definitions, sizing considerations, and financial viability. It emphasizes the importance of matching generation to a building's demand while considering costs, potential grid connections, and compliance with regulations. The document also discusses financial incentives and the need for thorough calculations of all associated costs.
Untangling the Complexity of On-site Electricity Generation
- 1. Energy Managers Association On Site Generation Considerations
- 2. On-site generation For this presentation, on-site generation is:- • smaller sized generation generally below 1 MW • any technology where generation is connected to feed directly into a buildings systems, as opposed to being directly connected to the National Grid • the equipment can be building mounted or standalone near a building but connected to it • the equipment may be owned by the building or supplied via a private wire connection • the generation output may all be consumed on site or any excess exported
- 3. On-site generation sizing • On-site generation tends to be sized to fit a buildings basic demands such as its base load, as opposed to installing the largest amount possible • Imported energy is much more expensive than what you may be paid to export so high export volumes can impact financial viability
- 4. 00.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00 80.00 00:00 00:30 01:00 01:30 02:00 02:30 03:00 03:30 04:00 04:30 05:00 05:30 06:00 06:30 07:00 07:30 08:00 08:30 09:00 09:30 10:00 10:30 11:00 11:30 12:00 12:30 13:00 13:30 14:00 14:30 15:00 15:30 16:00 16:30 17:00 17:30 18:00 18:30 19:00 19:30 20:00 20:30 21:00 21:30 22:00 22:30 23:00 23:30 EnergydemandkW Time of day Average daily electricity consumption profiles Average Monday consumption Average Tuesday consumption Average Wednesday consumption Average Thursday consumption Average Friday consumption Average Saturday consumption Average Sunday consumption Min consumption seen
- 5. 00.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00 EnergydemandkW Average daily electricity profiles Average grid consumption Average solar generation Example of 100kW of solar PV installed
- 6. Site grid consumption (kWh) Potential solar generation (kWh) Monthly solar absorbtion (kWh) Monthly solar absorbtion (%) Export (kWh) Jan 35,782 1,541 1,541 100 0 Feb 34,216 3,534 3,534 100 0 Mar 34,574 7,432 7,432 99 53 Apr 29,111 10,516 10,516 98 265 May 30,007 13,221 13,221 96 576 Jun 19,819 15,290 15,290 92 1,253 Jul 27,901 15,782 15,782 93 1,258 Aug 29,037 10,850 10,850 97 333 Sep 27,931 8,213 8,213 98 204 Oct 31,711 4,952 4,952 100 1 Nov 33,173 2,613 2,613 100 0 Dec 37,130 1,554 1,554 100 0 370,390 95,500 95,500 96 3,943
- 7. 00.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00 80.00 90.00 EnergydemandkW Average daily electricity profiles Average grid consumption Average solar generation Example of 250kW of solar PV installed
- 8. Site grid consumption (kWh) Potential solar generation (kWh) Monthly solar absorbtion (kWh) Monthly solar absorbtion (%) Export (kWh) Jan 35,782 3,853 3,853 99 23 Feb 34,216 8,835 8,835 94 538 Mar 34,574 18,581 18,581 82 4,212 Apr 29,111 26,290 26,290 74 9,396 May 30,007 33,053 33,053 72 13,084 Jun 19,819 38,225 38,225 69 17,542 Jul 27,901 39,456 39,456 67 19,036 Aug 29,037 27,125 27,125 74 9,703 Sep 27,931 20,534 20,534 75 6,924 Oct 31,711 12,380 12,380 87 1,866 Nov 33,173 6,532 6,532 97 235 Dec 37,130 3,886 3,886 100 2 370,390 238,749 238,749 74 82,562
- 9. On-site generation sizing • On-site generation tends to be sized to fit a buildings basic demands such as its base load, as opposed to installing the largest amount possible • Remember that imported energy is more expensive than what you are paid to export so high export volumes can impact viability • Consider if generation levels and patterns still fit a buildings requirements out of normal operating hours • Oversized CHP can lead to excess heat being dumped, destroying financial viability • Battery storage could be considered for excess electricity generation to prevent export. Heat storage could be considered if excess heat is produced
- 10. Connecting generation to the grid • For any grid connected site, generation rated at more than 4kW (16 Amps per phase) has to obtain permission from the local DNO to be connected, even if all generation is used on site • This is classed as a G59 connection • DNO’s review applications for connection based on a network’s available capacity and it’s ability to cope with local generation • Local generation can raise system voltages, create imbalance, produce harmonics, flicker etc. • You may get approval but on condition that you prevent any export or a grid upgrade may be required at your cost • DNO’s usually provide budget prices or full feasibility studies.These used to be free of charge but this may vary in future along with the type of connection offered © EMA
- 11. Grid connection for generation • All G59 sites require permanent protection that prevents generation if the electricity does not conform with statutory requirements • A G59 “panel” is usually fitted to the generation equipment or the site to comply with this requirement • To commission generation, G59 witness testing is undertaken by the DNO and is likely to be required for most installations • Testing may not be required for type tested systems up to 50kW • Don’t forget the need for metering in your connection, potentially import and export © EMA
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- 14. Building connecting of generation Generation providers should provide a full solution but what should you consider? • How and where will you connect into the buildings infrastructure? • You need to be able to electrically isolate at both cable ends • The connection point for electricity and heat and the cabling and pipework through a building needs to be rated for full output • Equipment such as inverters may be required and needs to be housed • Will generation cause problems with any sensitive equipment? • Consider the effects of rising and varying voltages from generation and any possible harmonic impacts on site equipment • Is there existing standby generation on site? Does it need to be interlocked? © EMA
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- 18. Financial incentives • Each kWh consumed on site prevents import from the grid, avoiding wholesale cost and all use of system charges • RO now closed to new entrants and FIT’s only available up to March 2019.They are technology and installation size specific but once accredited, paid at a fixed, inflation linked rate for 20 years • Third party funding sources are still available • Ensure financial returns are calculated using sensible figures, especially if being quoted by a third party • Ensure all costs are taken into account as quotes may ignore equipment or services not provided by the supplier • Ensure you include maintenance costs as well as those for removal © EMA
- 19. CHP finances • Financing for CHP needs to take account of the cost of electricity displaced, the current fuel used to generate heat, the fuel that the CHP will use as well as maintenance • Delivered costs of electricity are rising faster than most other fuels so CHP viability may increase • If the current heat source in a building is not natural gas but another such as fuel oil, then financial viability should be better • Ongoing costs of any new fuel needs to be considered. For example, a biomass CHP may be viable now but what will the price of wood chip be in 10 years? © EMA
- 20. Summary • Ensure generation fits your buildings demand and profile • Ensure it can be connected safely and correctly • Ensure you can get an agreed grid connection • Review lifetime income streams and costs • Ensure sensible figures are used in projections including full installation, tariff, maintenance and disposal costs © EMA
- 21. Thank you MarkTaylor Taylor Made Energy Solutions Ltd Mark.taylor@tmenergysolutions.com 07785 313179