Latent Power Turbines (TM) -Wind turbines inside a can
Patent application Nos. GB 0807276.1, 0618171.3, 0903879.5
Climate change – Our moral dilemma
What should we do?
warming or postpone our plans for generating green energy until
the recession is over?
Fortunately research at Lancaster University suggests that a new generation of
Latent Power Turbine
could produce electricity that is both cheap and clean.
The big engineering breakthrough is that LP Turbines can operate using low grade heat at 100oC or cooler. This will allow coal, gas and nuclear power stations to generate more electricity without consuming more fuel.
A problem solver
Solar powered LP Turbines would allow all EU countries to meet their electricity demands in summer. But Mediterranean Greece, Italy, Spain, Portugal and Cyprus could produce additional electricity for splitting water into hydrogen and oxygen.
The hydrogen would be used to fuel LP Turbines in winter. And, in liquefied form. be used as pollutant free transport fuel. - No more industrial smog to harm our kids and asthma sufferers.
Here is one of our glasshouse designs for harnessing solar energy at a lower unit cost than using solar panels.
Figure 1 A cross section through a glass house as used in warm Southern European countries. By adding air ducts and using the waste heat to drive LP Turbines clean low cost energy could be generated.
A problem solver for the Middle East?
The Arab Spring was triggered by one man’s despair at not being allowed the dignity of honest work.
Latent Power Turbines could stimulate low carbon wealth, energy and food production in Afghanistan, Iran, Israel and a future Palestinian state.
On the rest of this web page we will concentrate on some applications for Latent Power Turbines.
Summary of applications
efficiency of fossil fuel power stations.
Reducing the cost of
carbon capture processes.
Converting low grade
industrial waste heat into electricity.
Industries as diverse as steel manufacturing and potato crisp production would benefit.
efficiency of solar thermal power stations.
efficiency of geothermal power stations.
Reducing the operating
pressure and temperature of nuclear reactors without reducing power
Air conditioning large
buildings while producing power instead of consuming it.
temperature and humidity in underground railway tunnels.
away from the grid in warm climates.
production and water desalination units.
Glass house plant
propagation in arid climates.
energy from sea water to drive LP Turbines in winter.
Delivering a hydrogen economy.
1 Improving the efficiency of fossil fuel power stations.
Figure 2. The steam turbines used in fossil and nuclear power stations are not very efficient. A typical coal fired power station can only exploit about 40-50%% of the energy fed into the turbine. The remaining energy is trapped as latent heat in the “cool” turbine exhaust steam. In this illustration the cooling towers at Ferrybridge power station are dumping the waste heat into the atmosphere. (Original photograph courtesy of SSE.)
Figure 3. Steam turbines dump a lot of waste heat into the environment. The very pure water required for turbine operation is re-circulated, but the secondary cooling water used to condense the steam at the end of the turbine cycle is gradually lost to the environment. This loss can be a serious problem during prolonged draughts.
The alternative to cooling towers
Latent Power Turbines could be powered by the waste heat we currently throw away.
This diagram shows how we could do it.
4. The principle of an LP Turbine
based steam condensing unit. A large array of such units would be
The air passing through the turbines is dry at one atmosphere pressure. The steam condensing on the outside of the turbine tube is below atmospheric pressure.
Figure 5. LP Turbines can be used to increase power output and reduce fuel costs.
The need for secondary cooling water is also eliminated.
2 Carbon capture
Fossil fuel power stations will only become truly “green” if the carbon dioxide they produce can be captured and buried. The snag with existing techniques for carbon capture is that they are very energy intensive and are predicted to increase energy costs by about 25%. In Appendix 2 of our technical page we explain how LP Turbines could convert carbon capture into a net energy generating process.
3 Nuclear power stations
Nuclear reactors could run cool for the
limited purpose of producing atmospheric pressure steam.
Compared with conventional reactors, cool nuclear would be very safe and produce less nuclear waste per unit of electricity.
Figure 6.Atmospheric pressure nuclear power stations would generate all of their electricity using LP Turbines.
This change to more benign steam requirements could force a complete rethink on reactor design. Hopefully, it will one day result in the construction of thorium based nuclear reactors. Thorium reduces the nuclear waste problem and cannot be made into bombs.
4 Micro-power generation
The design shown in Figure 4 would be useful in environments where there is also a demand for moist air cooling.
Combined micro-power and solar desalination plants are a feasible option. Solar radiation would be used to evaporate water vapour from brine and an LP Turbine would act as the heat sink for vapour condensation.
5 Large scale solar thermal power stations
Figure 1 is reproduced below.
extraction ducts can be added to existing glass houses. When coupled to LP
Turbines this converts them into solar power stations.
The power generated depends on location, time of day, cloud cover etc. In southern Europe we estimate this will averages out at about 500 kWh/m2.
This is higher than the power output for photo-voltaic cells and a lot cheaper.
5.1 Extract heat from a warmer layer of the atmosphere
At night the ground temperature in warm arid regions falls rapidly. But a warmer layer of air,100 metres or so above ground level is common. This can be tapped into using a tall chimney.
Figure 8. The "chimney" works in reverse, drawing down relatively warm air at night.
Each kW-hour of power generated will also condense out about 1.5 litres of water.
Increasing glass house productivity
Some of the electricity can be used for night time illumination of the glass houses. This will increase crop yields.
5.2 Combined solar thermal and gas fuelled power stations
Natural gas would be burned to produce additional heat when the solar power is inadequate.
The combustion process produces water vapour and carbon dioxide. Consequently, LP Turbines will be inherently more efficient than conventional gas turbines because they can harness the latent heat released when the water vapour condenses. The carbon dioxide would be fed back into the glass houses to speed up the rate of plant growth.
Combined solar and gas fuelled power stations would be a good option for Southern European countries because they could operate at full power throughout the year.
Rice growing paddy fields produce methane which is a potent greenhouse gas. This climate change threat could be converted into a virtue by growing rice inside the LPT glass houses and using the methane rich air as the air supply for natural gas combustion. (Methane is the principle component of natural gas., so gas purchase prices would be reduced slightly.)
5.3 Combined solar thermal and bio fuel
The bulk of the bio fuel could be grown inside the glass houses. A dedicated double glazed glass house would be assigned for drying out the fuel. The moist air produced by drying the fuel would be used to power LP Turbines.
5.4 Combined solar and geothermal
The efficiency of geothermal power stations can be improved by replacing conventional steam turbines with LP Turbines. Combining solar and geothermal LPT systems offers a further advantage: the geothermal rock can be “rested” during daylight hours, allowing it to warm up again.
5.5 Extraction of latent heat of fusion
Dry air LP Turbines can operate below 0oC.
Latent heat could be extracted from brine as pure water freezes out to form ice. If brackish or sea water is available locally, the system would also deliver freeze desalinated drinking water.
Figure 9. Ice is frozen out at night, releasing latent heat to power the LP Turbines.
6 Using LP Turbines to create tourism and engineering jobs in Southern Europe
LP Turbines could deliver power and water to coastal communities. As a bonus, floating steam generators, used to supply energy to the LP Turbines could act as pontoon harbours.
Figure 10. A pontoon version of the solar powered LPT power station would provide moorings for boats. It would produce 1.5 litres of drinking water for every kW-hour of electricity generated.
A bonus for Greece
Designing and building the pontoons could revive the Greek shipping industry.
Figure 11. Greece, Italy, Cyprus, Portugal and Spain could become the green energy generating sunshine economies of Europe.
7 LP Turbines could make the deserts bloom
(Map courtesy of Guinness Publishing.)
Fig. 12. The World’s
In addition to the true deserts shown, all the populated continents have extensive tracts of semi-arid scrublands. These could become economically productive regions if solar LP Turbine systems were introduced.
Estimating the desert area needed to be colonised by solar LP Turbine units to meet our TOTAL energy needs
(i) The mean annual direct solar energy density for the Sahara desert is 2.9 x 103 kWh/m2. For comparison, this is about twice the solar energy density in southern Italy. 
(ii) For the following desert calculations we will assume a cautious value of 1.0 x 103 kWh/m2/year. (=109 kWh/km2/year). We will also ignore any energy captured from the desert air at night.
Sample primary energy consumers (Primary energy = coal + oil + gas + nuclear + renewable)
Total primary energy consumption/yr (x1012 kW h)
Area of solar LPTs required to generate equivalent amount of energy (km2)
Regional desert(s) used for comparison
Total area of desert(s) (kn2)
2.4 x 103
26.6 x 103
North American (Mojave + Sonoran)
Whole world 
142.3 x 103
All of Worlds true deserts
15 013 x 103
 Desert areas, The Guinness World Data Book, ISBN 0-85112960.9
 Italian National Agency for New Technologies, Energy and the Environment, 2005, "Harnessing solar energy as high temperature heat".
 IEA Key energy statistics 2010
(i) These calculations are presented simply to show that generating all of the worlds energy needs using desert solar energy is possible. We are are not proposing that this should be done.
(i) Don't forget, these power generating glass houses also produce cash crops and create jobs in the horticulture industry.
8 How to make
replanting the rain forests profitable
– without subsidy or handouts!
Daytime rain forest temperatures are lower than in deserts at the same latitude, but the air remains warm and humid throughout the night. This will allow LP Turbine power stations based in rain forests to operate 24/7 without any form of backup heating.
Figure 13. This is a plan view of a rain forest based LPT power station. (Not to be confused with a Dalek on a bad hair day!)
Replanted rain forests can earn extra money by acting as carbon sequestration sites. The following vertical cross section through an LPT moist air conduit and adjacent land shows how.
The archaeological evidence suggests that biochar can remain locked in
rain forest soil for more than a millennium. Rain forests growing on
improved soil have a lower canopy and denser undergrowth. This should
improve the moist air holding capacity of the forest. [“Hand made”, New
Scientist, P42, 4 June, 2011.]
The soil inside the tunnels will will be protected from physical erosion by violent tropical rainstorms.
9 Extracting heat from sea water to provide fuel for LP Turbines
The average sea water temperature around the British Isles in winter is
about 6oC. This combined with the fact that sea water freezes
at about -2oC, suggests that Britain could employ offshore LP
Turbine units to generate power all year round.
Figure 15. Pontoons floating offshore could become the homes for large LP Turbine power stations. The same design could adapted to provide power for marine vessels and buoys.
Strategically placed pontoons could also provide a degree of storm protection for vulnerable stretches of coastline such as at Dawlish, UK where a length of exposed railway track was swept away in February 2014. As a tourist bonus, the pontoons could be linked to the shore by a gangway, with the pontoon roofs being used as a create a promenade.
10 Reducing air temperature and humidity in underground railway tunnels
Figure 16. Heat trapped in underground tunnels could be converted into electricity.
11 Converting fracking wells into geothermal power sources
Fracked gas is warm and rich in water and organic vapours. LP Turbines could be used to cool the raw gas and strip out the vapours. Scrubbing the gas in this way would generate additional power without increasing greenhouse gases.
When the wells are exhausted they could be enjoy an extended life as geothermal heat reservoirs.
Cold dry air could be pumped into the wells and warm moist air for driving LP Turbines extracted. Heat of compression would be removed from the dry air before injection and also used for driving LP Turbines.
In mild weather the LP Turbines would extract heat from the atmosphere, leaving the underground heat reservoirs to make a thermal recovery.
Optionally, the electricity could be used for splitting water into hydrogen and oxygen. The existing natural gas distribution network would then be used for distributing the hydrogen to customers.
12 How low can they go?
If LP Turbines are used for extracting thermal energy from atmospheric air, then the outer surfaces of the turbine unit will start to ice up when the air temperature falls to around 5oC.
SLIPS ice repelling coatings being developed at Harvard University may solve this problem.
If it works efficiently, SLIPS would allow countries with damp cool climates, such as the UK, to generate all of their electricity using LP Turbines, all year round.
Figure 17. The steep jacket walls would encourage any ice that did form to drop off under gravity. The air inside the jacket would be dried by running the LP Turbine for several minutes at about 5oC, so that the water vapour fraction of the air condensed out.
SLIPS technology may also be useful for reducing drag inside LP Turbine systems. This would allow the air to travel through the turbines at higher speeds, increasing their power to volume ratio.
13 Current state of development (May 2014)
A proof of
concept LP Turbine is currently being built by C-Tec Innovation at Capenhurst
near Chester, UK. Sheffield University is advising us on the turbine
Our primary goal is to obtain evidence that the design is viable. If we are able to generate a net output of electricity, this will be a bonus.
This project is supported by the Technology Strategy Board and the
Engineering and Physical Science Research Council.
[TSB/EPSRC research funding of £98,400 granted.]
We hope to have basic computer simulation results by late May2014, with the first hard experimental evidence about a month later. A draft technical report should be available by the end of the year.
As we explain on our LP Turbine theory
page, further investment will be necessary to scale up the plant and
refine the turbine unit design.
Enquiries from potential partners and investors are welcome.
Latent Power Turbines are almost too versatile. They could destabilise world energy markets if there is no international long term plan for their implementation. Energy policy planners are invited to contact us to discuss the issues.
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