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By Jorge Moreno, Environmental and Building Technologies, Frost & Sullivan With more end users focusing on reducing energy costs, energy-saving water-to-water heat pump (WTWHP) chillers are being deployed to reduce a facility's utility bills. A WTWHP chiller is a water-cooled chiller that is designed to produce hot water at a specified temperature. The use of a WTWHP chiller is very similar to a conventional centrifugal chiller except for the fact that it uses two compressors, slightly different piping configurations, and more advanced controls in order to balance cooling and heating loads. In a conventional chiller, cold water is produced for comfort cooling, and the hot water that is extracted from the refrigeration process goes into a cooling tower and is released into the atmosphere. In a WTWHP chiller, this hot water is captured and relocated to a second heating stage, where the temperature is raised and the water is used as a heating source for a building's heating requirements. The key strength of WTWHP chillers is the high coefficient of performance (COP) that translates into significant energy savings and a shorter payback period. On the other hand, the key weakness is that it can only provide such benefits in a narrow range of applications primarily due to its coincident need for cooling and heating requirements throughout the year to ensure efficiency. A coincident need means that the application demands sizable water heating load along with the typical high cooling requirements in summer, and a sizable chilled water load along with the typical heating requirements during winter. Cooling output is directly dependent on the demand for heating, and vice versa. Consequently, in the absence of sufficient heating requirements, there is only a limited amount of cooling that can be produced. Any excess heating or cooling cannot be stored and hence, it is critical to align the cooling with the expected heating requirements. Coincidentally, in the absence of suf

this may make international news for south africa - the "europe of africa" - but it's commonplace in uganda. load-shedding? we don't have it for just a few hours in the afternoon, that would be luxury. no, load-shedding in uganda tends to be on a 24-hour-on-24-off cycle. yes, that means for 24 hours you have electricity, then for the next 24 you don't. there's some elaborate schedule for knowing when load-shedding's going to hit your part of town; sometimes the schedule gets printed in the paper and (almost) always it isn't followed.

Batteries have to contain all of the chemicals on both sides of their energy releasing equation. The very best batteries available today can store about 0.4 MJ/kg (0.05 kw-hr/lb) including the cases and safety systems. In contrast, gasoline carries about 46 MJ/kg (5.7 kw-hrs/lb).\n\nEven with a 20% efficient IC engine, a gasoline tank stores 20 times as much energy as a battery of equal weight. As the vehicle is moving it gets rid of some of that weight. Battery powered vehicles must carry the full weight of their energy source.\n\nThe energy density difference also plays a key role in the time that it takes to put more energy back on the vehicle once a fuel load is consumed. A two minute fill-up of a 12 gallon tank puts the equivalent of 87 kilowatt-hours into the vehicle, again, taking into account the 20% thermal efficiency.\n\n87 kilowatt-hours in 2 minutes works out to 2.6 MegaWatts. Even with a 220 volt connection, that would require about 11,800 amperes of current. Just imagine the size of the electric cables for that current.\n\nThere are certainly places and applications where electric vehicles have a role, but it is worth remembering that at least five or six generations of engineers have looked very hard at trying to meet transportation needs and they keep coming back to the same fact - when you want to move a vehicle, you need power, (energy per unit time).

Insensys, the leading provider of fibre optic load measurement systems for blades and Garrad Hassan the leading developer of pitch control algorithms have combined forces to develop an integrated package which enables turbine manufacturers to achieve significant reductions in rotor, shaft and tower loads. The collaboration is non exclusive and both organisations will continue to offer products and services independently of each other.

Two strong potential candidates for the Next Big Thing in cleantech venture capital are nuclear and carbon capture and storage. I've spoken with numerous VCs recently who are looking for innovative ways to play in nuclear power. Bets have already been made by VCs in small-scale nukes, hot fusion, and technologies related to big-scale nukes. The hope is to find a low-cost solution that is practically zero carbon emissions and also provides reliable "base load" power. So in other words, the hope is for a lower-carbon replacement for coal power. The challenges are also significant, however, not least of which being time to market for any new innovations, as this interesting article illustrates. With the recent news that the DOE will be putting $2.4B into carbon capture and storage, and its inclusion in emerging climate legislation, it's also clear that CCS will be leaned upon as a hoped-for way of making our existing coal-fired generation infrastructure less impactful on the atmosphere, while still preserving its value as low-cost baseload power. So in other words, the hope is for a lower-carbon "fix" for coal power.

With the best of intentions ...

Wind comes out the clear winner. Concentrated solar power, geothermal, solar photovoltaics, tidal, wave, are good additions to the mix. Hydroelectric is added for its load balancing ability. Nuclear and coal are less beneficial. Corn and cellulosic ethanol should not be included in policy options. Hopefully, the next administration will be wise enough to follow Pr. Jakobson's recommendation . . . and align its subsidies with the right kind of technologies.

The report presents how climate will change according to climate models concerning the planning and building of electric power networks from the present state to the period from 2016 to 2045. The essential impacts of changes in weather conditions on planning and building of electric network are defined regionally based on the climate change scenarios. The importance of the effects is shown as costs and failure durations for different line structures. Moreover, the influence of the climate change on the loading capacity of the power system components is presented. On the basis of all these factors it will be judged how strong an effect the climate change has in the present electric power network and how one should be prepared for it.

The target was greeted with wide skepticism, including from the Renewable Energy Foundation, which accused the government of "green exhibitionism".

But note that Nick Jenkins supported the idea on TV News without reservation! Note also that around 40% - 13GW - of this generation would be off the coast of Scotland. The interconnectors to England (where the demand is) are about 2.5 GW and already fully loaded. Nobody talks about the need for connection.