Tuesday, July 05, 2011

The Future Electric Society

Electricity is what 4 recent, integrated visions have in common about the future of energy.In this presentation, we introduce these visions, their common elements and their far-reaching implications for the future of energy. Join the debate here or on LinkedIn.

Thursday, May 19, 2011

How much energy will we need?

According to David MacKay's book Sustainable Energy - Without the Hot Air, the UK will need 70 kWh/pp/day to cover final energy needs for electricity, transport and heat. This is equivalent to 100 GJ/pp/yr of final energy.

In his book Energy at the Crossroads, Vaclav Smil argues that we can get by with 50-70 GJ/pp/yr - 70 GJ was roughly the energy consumption of Japan / France in the seventies.

The above graph comes from the recent Energy Report and gives an overview of estimates for primary and final energy needs towards the middle of this century.

The good news is that - in a 100% renewable system - the distinction between primary and final energy fades, and that we could suffice with 300-500 Exajoules of annual energy consumption. In a world of 9 billion people, this means 33 - 55 GJ/pp/yr, after we electrify personal transport and massively insulate buildings.

Monday, May 16, 2011

Four integrated energy visions

Solar Array récupéré de http://en.wikipedia.or...Image via WikipediaVision #1: Sustainable energy without the hot air
In his book, David Mackay works out the numbers for the UK. He uses a common unit (kWh/pp/day) and uses this to calculate daily energy needs for electricity, heating and transport, concluding that UK could be run on 70 kWh per person and per day. Then he reviews which sources could contribute to this demand, and develops 5 plans for powering Britain.

Vision #2: Searching for a miracle
This report by Richard Heinberg is all about the Energy Return on Energy Invested (EROEI) of various energy sources. It reviews 18 energy sources, and comes to a worrying conclusion. EROEI is decreasing rapidly.

Both experts emphasisize the need for energy conservation and on the advantages of electricity as an energy carrier. They see only very limited potential for bioenergy. Both see major potential for wind power, photovoltaics and concentrated solar power.

Vision #3: Providing all global energy with wind, water, and solar power
In this paper, Mark Jacobson estimates that a 100% renewable system will require 3,800,000 5 MW wind turbines, 49,000 300 MW concentrated solar plants, 40,000 300 MW solar PV power plants, 1.7 billion 3 kW rooftop PV systems, 5350 100 MW geothermal power plants, 270 new 1300 MW hydroelectric power plants, 720,000 0.75 MW wave devices, and 490,000 1 MW tidal turbines. It is one of the first global visions for 100% renewables, relying primarily on electricity.

Vision #4: The Energy Report
This report is a joint project between WWF and Ecofys also proposes a global, 100% renewables vision. Like the Jacobson report, it foresees a major role for electricity - a common characteristic for the 4 visions, but it also expects major contributions from bioenergy, e.g. for marine transport, aviation and industrial heating processes.

For these last 2 visions, Leonardo ENERGY is organising webinars on June 14 and June 16 where the respective authors will present their findings.

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Tuesday, April 26, 2011

Solar Photovoltaics at a total cost of 1 $/Watt can change everything

GAINESVILLE, FL - APRIL 15:  Tom Doughty (L) a...Image by Getty Images via @daylifeGary Hunt has a post yesterday on Energy Secretary's Steven Chu's Sunshot initiative targeting 1 $/Watt as total cost for going solar. For sunny climates, where each kW can produce as much as 1,500 kWh of electricity, worth a couple of 100 dollars at current retail prices, an investment of a 1000 $/kW will give a much better return than the financial markets.

Unfortunately, the initiative targets bulk solar power plants of 100s of MW. For small-scale residential systems, the 1 $/W target is more distant, and may never be achieved for typical systems of 3-5 kW which carry too much planning, design and installation overhead.

For utilities and project developers with deep time horizons, this cost target enables bulk electricity generation in the range of 5 to 10 c/kWh. If the market massively invests in this technology, solar PV may even help to reduce electricity prices.

Comparing this with current retail prices of electricity, a rate of 5-10 c/kWh give some margin to invest in smart grids for balancing, solving any problems that may occur during the day. However, with massive investment in solar photovoltaics, and despite equally massive deployment of demand management, smart grids and strongly integrated regional transmission systems, substantial long-term storage will be needed. According to The Energy Report, this can be provided by a combination of pumped hydro, compressed air storage and hydrogen.
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International Zero-Energy Housing

Since buildings are major energy users, zero-energy building concepts are one of the major potential contributors to a sustainable energy system. This presentation from innovolve presents an International Zero-Energy Housing Initiative, demonstrating that the concept works for a wide variety of dwelling types in various climates. After the examples, the presentation introduces some of the technologies used, and what needs to be done to have a massive zero-energy housing movement.