The Climate Spectator has an article on research into a solar powered air cooling system which could help reduce the spiralling cost of network transmission expansion required to meet the growing summer peak loads created by air conditioning units - A chilling future for solar power.

Everyone seems pretty comfortable with the idea that the energy from the sun can be captured to heat stuff and create electricity. But what if we were able to use it to address one of Australia’s greatest needs: how to cool things down, particularly the air inside your home; and one of its greatest challenges – reducing peak loads on the network?

This is one of the ideas being developed by the CSIRO at its Energy Research Centre in Newcastle. And the technology – known as Solar Cooling – is now at the point of commercialisation. And it is so simple it can be bolted on to the solar hot water systems that are already so prevalent in suburbia – and add space heating in winter and cooling in summer to the hot water that is already delivered by the solar collectors.

The irony of this development is that it offers the opportunity for a renewable energy source to provide a solution for a problem it is often blamed for creating – rising electricity costs.
The reality is that the greatest component of rising energy bills is the cost of network upgrades, and the biggest reason for these is the growth in peak energy demand, driven largely by the rush to install household air conditioning systems, which now account for around 50 per cent of peak demand on some networks.

Indeed, such is the scale of the rollout of domestic air-con, and its impact on networks, that it now qualifies as the most heavily subsidised sector of the electricity grid – far greater than rooftop solar, or large-scale wind farms.

For every $1000 invested in an air-conditioning system, it is estimated that another $3000 is required to upgrade the network. That translates into an added cost of $100 per year on the electricity bills of those who either choose not to have air-con in their home, or who can’t afford it.

Reducing peak demand is one of the biggest challenges facing energy market operators. In Australia, it is estimated that one quarter of the nation’s electricity costs go to catering for around 40 hours of peak demand – those occasions of extreme temperatures when everyone turns on their air-con at the same time and when the electricity demand is nearly doubled. If this technology based around solar panels on the roof can be rolled out at scale, it could offer one of the best opportunities to significantly lower those peak loads and reduce the need to upgrade and expand networks and help flatten the anticipated spikes in domestic electricity bills.

The principle behind Solar Cooling systems being developed by the CSIRO is simply to integrate technologies that are already understood – the rooftop panels on the roof that heat the water, and which can then be used to heat air; a desiccant wheel to dry the air; and evaporative systems to cool the air.

Stephen White, the manager of the CSIRO’s Energy for Buildings division, says the advantage of this system is that it can operate at relatively low temperatures – 50°C to 70°C – which are common for solar hot water systems.

Incoming hot, moist, humid air is dehumidified using a desiccant such as a silica gel on a rotating wheel to create a dry air stream which is then cooled using an evaporative cooler. The desiccant absorbs the moisture from the air. This material is then stripped of moisture (regenerated) using solar heat.

The CSIRO believes that electricity costs could be reduced by half – and would be a much more efficient use of resources, because the solar collectors would be in use all year round, while a conventional air conditioner system might be in use for just 7 per cent of the time.
“We see it as three in one solar thermal product for the home – a solar hot water system, and space heating in winter, and cooling in summer when the sun is shining the hardest," Dr White says. “It matches very nicely." It is likely that these systems will be able to bolt on to already installed solar hot water systems.

The CSIRO has already developed a prototype called REDEcool which can be used in households and is now looking for a manufacturing partner to help refine the design, and the costs, for mass production. Dr White says the capital cost of the system will be more than the $1000 that people pay for the air-con systems they buy from shops, but it should be cheaper than the $4000 network cost.

Earth2Tech has an update on efforts to connect the major regional electricity grids in the US - Xtreme Power Joins the Transmission Hub Project.

The startups that have teamed up to build a transmission hub to connect the U.S.’s three major grids in the east, west and Texas are adding another startup player for energy storage. This afternoon, Tres Amigas, the Santa Fe, N.M-based company behind the transmission project, announced that they have partnered with Xtreme Power, a startup which provides groups of batteries for energy storage for the power grid. In June, Tres Amigas also signed on startup Viridity Energy, which makes software that dynamically manages loads on the grid in terms of energy pricing, renewable energy generation and energy storage.

Tres Amigas’ plan is to build a so-called “SuperStation” — the mother of all substations — that would use superconducting cables from American Superconductor Corp. that can carry 5,000 MW of electricity, are super-chilled to minus 300 degrees Fahrenheit, and can boost the lines’ carrying capacity. The substation itself would act as a hub and balancing authority, and would convert the alternating current (AC) from the three grids into direct current (DC) and then back to AC in order to move the electricity back out onto the three grids in an efficient and reliable way.

Xtreme Power’s batteries would provide storage for the SuperStation to help balance the flow of electricity, and importantly, to enable the addition of more clean power, which is variable, depending on the wind and sunlight, which aren’t always available. Xtreme Power’s batteries would store and release power in response to fluctuations in demand and supply at the hub.

Six-year-old Xtreme Power is building this type of storage system for other clean power projects, including a 10-megawatt storage system meant to back up a 30-megawatt wind farm planned for the Hawaiian island of Oahu. The developer of the wind project, First Wind, recently received a $117 million Department of Energy loan guarantee for the project, and Xtreme Power said it will be managing not only its battery, but the entire wind farm’s output via its own smart grid network. Xtreme has also tested a 1.5-megawatt battery system at another 30-megawatt wind project on the island of Maui.

For its batteries, Xtreme uses a PowerCell battery chemistry that it calls a “chemical capacitor,” which it says can beat lithium-ion batteries in terms of energy storage, efficiency, cycle life and cost. CEO Carlos Coe told us back in March that Xtreme’s PowerCell battery tech acts more like capacitors: charging and discharging at high speeds, while at the same time, maintaining the qualities that make batteries better than capacitors for long-term energy storage.

Lou Grinzo has a look at the sources of electricity generation in the US and where the power is consumed (or wasted) - GOTW: Electricity Flow Diagram.

When the US Dept. of Energy recently released the latest edition of its Annual Energy Review, that naturally included updated versions of their “flow diagrams”, which are still the most useful set of graphics I’ve seen for understanding the sources and uses of all energy, coal, petroleum, natural gas, and electricity in the US.

This time around, let’s do electricity...

You can find links to all of the flow diagrams from the Annual Energy Review on the AER’s home page, in HTML and PDF format.

The things I find most interesting in this one include:

The relative sizes of the sources. Coal really is about half, as much as we wish it were otherwise, and oil is a barely perceptible sliver (don’t tell the media; they still love their decades-old conviction that the US still generates a sizable portion of its electricity with oil). Renewables, while still smaller than we’d prefer, is mostly conventional hydroelectric power.

Conversion losses practically leaps off the screen. This is (mostly) the energy lost in burning fuel to heat water to make steam to spin a turbine to pump electrons. When I show this chart to middle school students and tell them what “conversion losses” means, they give me the most withering, “Just how stupid are all you adults, anyway???” look. Aside from those awkward moments, it’s a good reminder that we decide things like how to generate electricity via economics, not energy or natural resource conservation.

Transmission and distribution losses are tiny. The almost universal misunderstanding among mainstreamers is that T&D losses are a huge factor in their electricity costs, when it just isn’t so. By comparison, conversion losses are 24.8 times higher.
The relatively even balance between residential, commercial, and industrial consumption. My guess is that while the commercial and industrial sectors are hardly paragons of environmental concern or even conservation purely for the sake of saving money, they’re probably on the whole much better than the residential sector. If my guess is right, then the low-hanging fruit for electricity conservation is in our homes and not at our jobs.

Transportation’s share of consumption is so tiny you almost need a magnifying glass to see it. How much do you think that will change, on a percentage basis, in the next ten years?

Not bad for one diagram, eh?

Science reports that a second family of (relatively) high-temperature superconductors has been discovered.

Superconductors are interesting from an energy transmission point of view because of the very low losses involved. The gain compared to other transmission methods is partially offset by the energy required to refrigerate the lines, so high temperature superconductors are an interesting advance for those considering building large scale supergrids - such as the US plan for a superconducting cable network covering the entire nation by 2030.

Researchers in Japan and China have discovered a new family of high-temperature superconductors--materials that conduct electricity without any resistance at inexplicably high temperatures. Physicists around the world are hailing the discovery of the new iron-and-arsenic compounds as a major advance, as the only other high-temperature superconductors are the copper-and-oxygen compounds, or cuprates, that were discovered in 1986. Those older materials netted a Nobel and ignited a firestorm of research, but physicists still don't agree about how they work, leaving high-temperature superconductivity the biggest mystery in condensed matter physics. Some researchers hope the new materials will help solve it.