THELION DEVELOPMENTS LTD

Transcription

1 THELION DEVELOPMENTS LTD A novel compressed air energy storage concept with higher efficiency levels but similar capital costs to conventional nonadiabatic compressed air energy storage.

2 CONVENTIONAL CAES Non-adiabatic compressed air storage is one of the cheapest but also least efficient energy storage methods at 55% RTE (round trip efficiency). On non-adiabatic systems, most of the energy lost is through the wasted heat of compression. Proposed adiabatic systems are more efficient (>70% RTE) but significantly more expensive than non-adiabatic systems. An external heat source such as open cycle gas turbine is required to increase performance.

3 COMBINED CYCLE Vs OPEN CYCLE GAS TURBINES In combined cycle arrangements, the hot exhaust gasses of the primary cycle are recovered in a steam turbine cycle. This steam turbine recovers about half of the available exhaust energy from the primary cycle. Although a steam turbine s exhaust has a high energy content, its temperature is too low for reuse (approximately 30 C). A novel cycle is proposed to recover this low grade energy in a useable form.

4 GAS ACCELERATION FOR LOW GRADE HEAT RECOVERY The key component of the novel cycle is the recuperating condenser which allows the compressed air to recover the waste energy from the steam turbine. High pressure gas is accelerated in a series of nozzles creating a temporary and reversible temperature drop to recover thermal energy. The illustration right is highly simplified and does not show aspects such as supersonic flow, parallel flows, and staged decompression and temperature absorption to avoid local freezing on the pipe-work.

5 A COMPRESSED AIR SYSTEM USING THIS CONDENSER The significantly reduced airflow (around 50% of conventional non adiabatic systems of similar output) allows for smaller air storage volumes, smaller air turbo-machinery, and consequently reduced heat of compression loss. Estimated round trip efficiency for the most basic low cost system using a preferred flow arrangement is 70% (air acceleration to Mach 1.4). The only novel component is the recuperating condenser, which contains no moving parts.

6 SYSTEM COULD BE INSTALLED IN COAL MINES There are a large number of available sites especially in the UK, continental Europe, and Northern America. Coal mines are technically validated for hydroelectric pumped storage. The proposed system has much smaller fluid volumes and far simpler technical requirements to an equivalent hydroelectric system. The system variant shown is water electrolysis / hydrogen combustion turbine based and therefore emissions free.

7 COMPARISON WITH MATURE ENERGY STORAGE TECHNOLOGIES Hydroelectric pumped storage (99% of world s existing capacity few new build plants) Relatively high efficiency levels of 70-75% round trip efficiency, quick ramping times (12 seconds). High CAPEX ( 2,200/KW or 360/KWh) long build times (10 years) plus shortage of conventional sites. Conventional non-adiabatic CAES (2 demonstration plants, not yet cost effective) Low capital costs of around 575/KW, 36/KWh. Fuel costs must also be factored in. Low efficiency of around 55%, rapid start-up times (seconds) but full efficiency takes 20 minutes. Adiabatic systems have higher efficiency levels (68-80% RTE) and higher capital costs. Lower emissions than combined cycle gas turbines, but not emissions free. Lithium Ion Batteries (leading contender for future storage but not yet cost effective) High efficiency levels (85% (DC to DC) ideal conditions), instantaneous power availability. High CAPEX- 250/KWh but uncertain operational flexibility e.g. lifespan after repeated cycles The Present System Efficiency levels of 70% for most basic system, or above 80% when using heat of compression recovery methods or other methodology from adiabatic systems. Capital costs similar to non-adiabatic CAES per KW, and significantly lower in terms of KWh. Using latest combined cycle gas turbine technology, full power output in around 20 minutes.

8 POTENTIAL MARKET SIZE MARKET VALUE PUBLISHED BY CONSULTANCY Lux Research indicates the global grid energy storage market is set to grow from $200 million in 2012 to $10.4 billion in The US market is estimated at $2.7 billion, and Europe $3.5 billion. The emerging economies of India and China, both of which suffer from air pollution, are also likely to represent substantial markets. OPPORTUNITY FOR REPLACING CLOSING FOSSIL FUEL AND NUCLEAR PLANTS In the UK, there are planned closures of 14.2GW of fossil fuel and nuclear plants in 2015, some of which could be replaced by a combination of intermittent renewable generation and energy storage. In addition, a further 5.1GW of UK nuclear is to close by The German nuclear phase-out is currently met by increased unsustainable brown coal. The US Environmental Protection Agency s regulations require up to 72GW of thermal plants to be replaced creating significant opportunity for new build. Many American nuclear plants are also due for closure.

9 PATENT STATUS, WAY FORWARD Patent Status UK patent granted and PCT application published and pending. Searches were positive for PCT. All IP is currently held by the inventor personally. Way Forward Via License Agreement Develop the product further, and then license to suitable organization, e.g. OEM External collaboration would also help inventor with securing grants inventor currently disadvantaged due to lacking required commercial experience. Early stage investment might comprise: 17,000 for proof of concept technical validation, preliminary design work from university plus some working capital For further development work, would need project management and commercial experience from partner. Would look at securing investment for grant matching. SME Instrument allows 70% intervention rate on projects up to 3,500,000 Total investment sought between 300,000 and 700,000 depending on desired project scope (e.g. basic system only? Emissions free hydrogen oxygen system? Incorporating adiabatic technology) Or Joint Venture / Consortium To Produce In House Requires additional professional input commercialise the product - e.g. existing SME? Could design and produce condenser equipment, and project manage product installation. Would use commercially available turbo-machinery, generator and electrical equipment, and heat exchangers other than the condenser.