Windmill on Ice or Water Bearings Has Low Friction at Low Cost


Simon Gripenberg, an artist from Finland, developed new types of vertical windmills, inspired by ancient Persian windmills and built from recycled materials. Most interestingly, the windmills float in water or spin on ice, so that Gripenberg manages to obtain low friction at low cost. [Read more…]

Wind Power System Made from Plastic Buckets

A wind power system made from plastic buckets is seen on boats at a floating village in Hanoi, Vietnam June 29, 2016. REUTERS/Kham

A wind power system made from plastic buckets is seen on boats at a floating village in Hanoi, Vietnam June 29, 2016. REUTERS/Kham

“Vietnamese families living in slums along the Red River in Hanoi are using red plastic buckets and old printers to help light homes, cook meals and slash electricity costs by as much as a third.

The recycled goods form the blades and motors of electrical generators that power old motorcycle batteries to illuminate lamps with a brightness equivalent to a 45-Watt light bulb.

Though the output generated is small, it makes a significant difference for families previously denied power because they lived too far from a power station or had to ration supply because of the expense.”

More pictures and information at Reuters: Plastic buckets, broken printers shine light on Hanoi’s poor. Via Playground Magazine.

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A World Made of Rotor Blades

public seating rotor blades close

Almost a quarter of a million windmills worldwide will need to be replaced by 2030. The rotor blades are made of valuable composite materials that are difficult to recover at the end of their energy generating life. New generation rotor blades made of glass or carbon fibre composite material have average lifespans of between 10 and 25 years. Recycling of glass fibre composite is possible though complex. Recycling of the more highly valued carbon fibre composite is currently impossible. In many EU countries landfill of carbon composites is now prohibited. Thus, many rotor blades at the end of their wind turbine life are currently shredded and incinerated. At current growth rates, by 2034, there will be about 225,000 tonnes of rotor blade composite material produced annually, worldwide.

The Dutch firm Superuse Studios has found a solution to the growing mountains of waste generated by the wind industry: making use of end-of-life rotor blades in design and architecture. The realised projects demonstrate the technical applications and potential for blade made designs and architecture. In their second life as design and architectural elements, rotor blades could be used for a further 50-100 years, or more. Blade made designs are durable, iconic, compete economically, and reduce the ecological footprint of projects in which they are used. [Read more…]

Trees as Indicators of Prevailing Wind Direction

trees as indicators of wind direction“In mountainous areas, winds are often complex and the available wind data are limited and provide little information on wind direction. One technique for determining the mean wind direction is tree flagging. Trees have been used for hundreds of years as an ecological indicator of wind direction, wind exposure and as a measure of the severity of wind and ice damage. This handbook will describe techniques for ‘reading’ the information written on the trees by wind.”

“Flagged trees only reflect the prevailing wind direction of the strongest winds, which may occur during only part of the year. Seasonal variations in the wind have a pronounced effect on the type of wind deformation and these effects are characterized in this handbook. Techniques for estimating the mean annual wind speed have been developed using indices of wind effects on trees. These indices have been calibrated on two widely distributed species of conifers. The main conclusions are that trees provide a simple, inexpensive and quick method for identifying promising locations where more detailed measurements can verify the wind potential.”

Trees as an indicator of wind power potential (.pdf), John E. Wade & E. Wendell Hewson, 1979.
Vegetation as an indicator of high wind velocity (.pdf), DOE report, John E. Wade & R.W. Baker, 1977

More low-tech wind power.

Wind Farms Can Be Made 10 Times Smaller

Size of wind farms “Modern wind farms comprised of horizontal-axis wind turbines (HAWTs) require significant land resources to separate each wind turbine from the adjacent turbine wakes. This aerodynamic constraint limits the amount of power that can be extracted from a given wind farm footprint. The resulting inefficiency of HAWT farms is currently compensated by using taller wind turbines to access greater wind resources at high altitudes, but this solution comes at the expense of higher engineering costs and greater visual, acoustic, radar and environmental impacts.”

“We investigated the use of counter-rotating vertical-axis wind turbines (VAWTs) in order to achieve higher power output per unit land area than existing wind farms consisting of HAWTs. Full-scale field tests of 10-m tall VAWTs in various counter-rotating configurations were conducted under natural wind conditions during summer 2010. Whereas modern wind farms consisting of HAWTs produce 2 to 3 watts of power per square meter of land area, these field tests indicate that power densities an order of magnitude greater [21 to 47 watts] can potentially be achieved by arranging VAWTs in layouts that enable them to extract energy from adjacent wakes and from above the wind farm.”

Small wind farm “The results suggest an alternative approach to wind farming that has the potential to concurrently reduce the cost, size, and environmental impacts of wind farms.”

Read more: ‘Potential order-of-magnitude enhancement of wind farm power density via counterrotating vertical-axis wind turbine arrays’, John O. Dabiri. Introduction. Research paper (pdf). Via Ecogeek

The Receding Horizons of Renewable Energy

Giant windmill 1 “Widespread installed renewable electricity capacity would be a very good resource to have available in an era of financial austerity at the peak of global oil production, but the mechanisms that have been chosen to achieve this are clearly problematic. They plug into, and depend on, a growth model that not longer functions. If we are going to work towards a future with greater reliance on renewable energy, there are a number of factors we must consider. These are not typically addressed in the simplistic subsidy programmes that are now running into trouble worldwide.

We have power systems built on a central station model, which assumes that we should build large power station distant from demand, on the grounds of economic efficiency, which favours large-scale installations. This really does not fit with the potential that renewable power offers. The central station model introduces a grid-dependence that renewable power should be able to avoid, revealing an often acute disparity between resource intensity, demand and grid capacity. Renewable power (used in the small-scale decentralized manner it is best suited for) should decrease grid dependence, but we employ it in such a way as to increase our vulnerability to socioeconomic complexity.

Giant windmill 2 Renewable energy is best used in situ, adjacent to demand. It is best used in conjunction with a storage component which would insulate consumers from supply disruption, but Feed-In Tariff (FIT) programmes typically prohibit this explicitly. Generators are expected to sell all their production to the grid and buy back their own demand. This leaves them every bit as vulnerable to supply disruption as anyone who does not have their own generation capacity. This turns renewable generation into a personal money generating machine with critical vulnerabilities. It is no longer about the energy, which should be the focus of any pubicly funded energy programme.

FIT programmes typically remunerate a wealthy few who install renewables in private applications for their own benefit, and who may well have done so in the absence of public subsidies. If renewables are to do anything at all to help run our societies in the future, we need to move from publicly-funded private applications towards public applications benefitting the collective. We do not have an established model for this at present, and we do not have time to waste. Maximizing renewable energy penetration takes a lot of time and a lot of money, both of which will be in short supply in the near future. The inevitable global austerity measures are not going to make this task any easier.”

Read more at The Automatic Earth. Pictures credit.