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Archive for the category “renewable”

Price of Hydrogen Production via Electrolysis


It was the old idea of the hydrogen economy (first use term: 1970): intermittent renewable electricity in –> hydrogen out. Storage problem solved. The idea got discredited for cost reasons. These reasons are no longer valid and hydrogen is making a come-back.

Basic fact: It takes about 50 kWh of electrical energy to electrolyze 9 liters of water to obtain 1 kg of Hydrogen.

Price hydrogen from electrolysis: 2-3 euro/kg

Energy density (MJ/kg):
Hydrogen: 143
LNG: 56
Diesel: 48
Gasoline: 46

[] – Hydrogen made by the electrolysis of water is now cost-competitive
[] – Hydrogen Economy
[] – Veel wegen leiden naar waterstofeconomie


IEA Renewables 2017

[] – Renewables 2017

The Forgotten Green Energy Champion Chile

Today Chile gets 45% of its electricity from renewable sources and intends to increase this to 90% by 2050… or earlier.

[] – Renewable energy in Chile
[] – Chile’s Energy Transformation Powered by Wind, Sun and Volcanoes
[] – “Chile’s electricity should be 100% renewable by 2040”
[] – The ‘Uber of Recycling’ Igniting Green Revolution in Chile

Read more…

Hans-Josef Fell – Das Tempo der Energiewende

German language video.

Hans-Josef Fell is one of the most important advocats of renewable energy in Germany. He was the man behind “feed-in tariffs”, introduced in Germany in 2000 and and set an example for the rest of the world.

Fell has bad news: the energy transition in Germany is stalling. Were in 2000, 7 GW of new capacity was installed, in the last few years it has fallen back to 1.5 GW. Big oil, coal and lignite producers are successful in slowing down the transition.

[] – Hans-Josef Fell

Renewable Energy Skeptic David MacKay

[] – David J. C. MacKay
[] – David MacKay official site
[] – MacKay’s magnum opus “Sustainable Energy — without the hot air” (pdf, 12MB)

German Grid Still Reliable Despite Growing Renewable Energy

Despite a growing share of renewable energy in Germany, the grid remains as stable as ever: the average German has on average to endure a 11.5 minute/year blackout. Although grid stability will become an increasing challenge, for the moment everything is still fine.

[] – Duitse stroomnet ondanks pieken windenergie superbetrouwbaar

Evaporation as a Renewable Energy Source?

A few basic facts about water:

Specific heat of water 4.2 kJ/kg/°C [*]
Heat of evaporation of water: 2256 kJ/kg [**]

[*] – energy required to increase temperature of water with 1 °C
[**] – energy required to turn 1 kg of water of 100 °C into vapor of 100 °C

In other words: it takes just as much energy to bring water from 46 °C to 100 °C as it takes to turn boiling water of 100 °C into water vapor of 100 °C. Or in other words: there is a lot of energy associated with phase change. That energy can be won back by condensing vapor back into water. This is what essentially happens in a steam engine: coal is used to heat water and turn it into steam. Next the steam is expanded in a cylinder where it is condensed. Part of the evaporation heat is converted into the desired mechanical energy or motion. Or think of stepping out of the shower dripping wet. You will feel cold because the drops on your body evaporate, which takes a lot of energy which is extracted from your body.

In nature evaporation and condensing of water happens on a gigantic scale, think of rain. Is there a way of capturing some of this energy for human purposes and convert it into useful energy? Scientists of the University of Columbia think there is. The place to generate electricity would by near the surface of lakes (uh-oh). Spores are attached to a surface, absorb water vapor and expand in volume. The useful energy is generated when the spores release the water as vapor which drives a motor. As MIT Technology Review previously reported:

“An eight-centimeter-by-eight-centimeter water surface can produce about two microwatts of electricity (a microwatt is one-millionth of a watt), on average, and can burst up to 60 microwatts.”

That would be 12.5 * 12.5 * 2 microwatt per m2 or 312 microwatt or 0.312 milliwatt/m2. Which is not too impressive to say the least. A solar panel of 1 m2 in contrast can bring you up to 150 Watt. That’s a difference of 48,000 in efficiency.


[] – Potential for natural evaporation as a reliable renewable energy resource
[] – Water evaporation could be a promising source of renewable energy
[] – Evaporation Engines Could Produce More Power Than Coal, with a Huge Caveat

Dutch Renewable Energy Subsidies Q1+Q2, 2017

Overview subsidized renewable energy projects in the Netherlands to the tune of 5.8 billion euro. Half of that amount went to solar projects. The other half mostly to wind, biomass and some geothermal.

[] – Hoe komt Nederland aan 20 procent duurzame energie?

IEA – The State of the Energy Transition 2017

Diagrams below:

Read more…

Hans-Josef Fell – Accelerating the Global Transition to 100% Renewable Energy by 2030

[source] Hans-Josef Fell

One of the main proponents behind the Energiewende in Germany is Hans-Josef Fell. Now he has written an article with a proposal how to speed up the global energy transition towards 100% renewable energy, enabled by the recent spectacular price declines. Fell says that 2030 should be possible. “80% energy from the region for the region” is the key to success in achieving 100% renewable energy.

Full story below:

[] – Accelerating the global transition to 100% renewable energy
[] – Hans-Josef Fell

All-Energy Glasgow 2017

[] – All-Energy 2017
[] – All presentations (scroll down)

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70%, 80%, 99.9%, 100% Renewables — Study Central

Pointer to articles that describe the feasibility of 70-100% renewable energy systems.

[] – 70%, 80%, 99.9%, 100% Renewables — Study Central

Blueprint 100% Renewable Energy Base for Germany

Hans-Martin Henning and Andreas Palzer of the Fraunhofer Institute for Solar Energy Systems in Germany have set up a computer model for a 100% renewable energy base for Germany and have used that model to find the most cost effective configuration. The result can be seen in the diagram.

The energy inputs are:

Source Power [GW] Annual energy [TWh]
Solar panels 252 246
Onshore wind 200 360
Offshore wind 85 297
Hydro-power 5 21
Electricity import 0 0

Scale the numbers up and you have the solution for Europe, with significant changes in numbers for individual nations. The cost of this renewable energy system would not be higher than our current fossil fuel based energy system.


Gud – “Gas und Dampf” (gas and steam).
KWK – “Kraftwärmekopplung” (co-generation. “power-heat-coupling”)
Solarthermie – thermal solar (solar collectors)
BHKW – “Blockheizkraftwerke” (co-generation. “block heat and power generation”)
Gas-Wärmepumpen – Gas-heatpumps
Pumpspeicher – Pumped hydro
Wärmespeicher – heat storage (water medium)
Wärmelast – heat load
WP – “Wärmepump” (heat pump)

[] – 100 % Erneuerbare Energien fuer Strom und Waerme in Deutschland
[] – 27 slides talk Dr. Hans-Martin Henning
[] – 66 slides talk Dr. Hans-Martin Henning
[] – Deutsche Energiewende klappt nur mit intensiver Wärmedämmung
[] – Two Directors Take Over as Head of Fraunhofer ISE

[] – Sichere Stromversorgung mit 100 % Erneuerbaren Energien ist möglich

[deepresource] – Norway Europe’s Green Battery
[deepresource] – Norway Wants to Become Europe’s Battery Pack
[deepresource] – The European Supergrid
[deepresource] – First Climate Neutral Power Station in The Netherlands
[deepresource] – Opel Ampera E (Chevrolet Bolt)
[deepresource] – Gold Mine North Sea
[deepresource] – Power to Gas
[deepresource] – MERITS Seasonal Heat Storage Breakthrough
[deepresource] – Hamburg Considers Large Scale Storage of Heat

Read more…

Can Society Run on Renewable Energy Alone?

Kris de Decker

The Flamish energy thinker Kris De Decker blogs at “Low Tech Magazine“, was guest author at “The Oil Drum” and writes for many prominent newspapers in Belgium, the Netherlands and the UK. De Decker presents a big picture view on the possibility of a 100% renewable energy society. De Decker preaches “low tech” if not “no tech”.

The article:

[] – How (Not) to Run a Modern Society on Solar and Wind Power Alone

The author admits that there is potentially more than enough renewable energy available. In Europe 10 times, in the US even 100 times present day electricity consumption, that’s not the problem. The real issue is intermittency. How can we guarantee that our energy grids remain stable, like they have been over the past hundred year, when we switch from fossil fuel to renewable energy? They author describes the intermittency of wind and solar in more detail and we assume he has done his homework. A first positive observation is that throughout the year solar and wind intermittency somewhat compensate each other. There is more wind in the winter months and more solar in the summer.

De Decker lists five strategies to combat the negative consequences of intermittency:

  • 1. Backup Power Plants. Don’t opt for 100% renewable energy supply but keep fossil fuel backup capacity alive. And since it regularly happens that no renewable energy is available at all, this would imply that all fossil fuel power generating capacity must remain in place. The only difference is with the present is that they will be (partially) idle for a long time. Essentially a hybrid system.
  • 2. Oversizing Renewable Power Production. “Solution”: build so much capacity that supply always matches demand. The author admits that this would lower the energy efficiency (EROI) because the energy system would over supply which necessitates switching power generation off.
  • 3. Supergrids. Another more practical way to combat intermittency is connecting large geographical areas into a single supergrid and use “statistics” to even out irregular supply. This would require a continental grid with much higher voltages and in Europe a renewed grid with twelve times more transport capacity.
  • 4. Energy Storage. The author claims that in the case of Europe, 400 TWh net storage capacity is needed or 1.5 months worth of consumption. Pumped hydro can supply 80 TWh and car batteries 7.5 TWh. The rest should be batteries.
  • 5. Adjusting Demand to Supply. The author (correctly) questions the necessity of “supply should always meet demand”. Why not consume energy if it is available. The Dutch of the 17th century for instance reclaimed new land by pumping it dry and sawed planks for their commercial fleet with wind power, despite its intermittency.

There is not much wrong with the article and De Decker basically supports the idea of a 100% renewable society even if he is skeptical that we can have a plug-and-play solution and instead advocates that we should learn to live with a less comfortable situation where demand will follow supply instead of the other way around.

Is he right? Eh no. He is ignoring the impact of other promising storage technologies. Take the blueprint of the 100%-renewable energy model as promoted by the renowned German Fraunhofer Institute. Note this is the overall energy picture, not just electricity. The model and numbers are for Germany, but can be scaled up for Europe, with adaptions in the numbers for the respective local situations:

[source] 100% renewable energy blueprint for Germany according to the Fraunhofer Institute

Summary in numbers:

Input: 542 GW intermittent renewable energy, mostly wind (200 GW) and solar (252 GW).

Storage: batteries 52 GWh, pumped hydro 60 GWh, power-to-gas (methane) 88 GW and other, see legenda:

Gud – “Gas und Dampf” (gas and steam).
KWK – “Kraftwärmekopplung” (co-generation. “power-heat-coupling”)
Solarthermie – thermal solar (solar collectors)
BHKW – “Blockheizkraftwerke” (co-generation. “block heat and power generation”)
Gas-Wärmepumpen – Gas-heatpumps
Pumpspeicher – Pumped storage (hydro)
Wärmespeicher – heat storage (water medium)
Wärmelast – heat load
WP – “Wärmepump” (heat pump)
Überschuss Wärme – Excess heat

Essential is the Energiesanierung (energy renovation) of buildings, which should result in a reduction of space heating energy requirement of 64.9% as compared to 2010 level.
According to the Fraunhofer Institute would the cost of this renewable energy system not be higher than our current fossil fuel based energy system.

[] – Kris de Decker
[] – 100 % Erneuerbare Energien fuer Strom und Waerme in Deutschland
[] – Wie Deutschland auf 100 Prozent Ökostrom umsteigen kann
[] – Stabilität im Zeitalter der erneuerbaren Energien

Airbus Electric Aircraft Roadmap

Airbus and Siemens signed an agreement recently with the aim to develop a hybrid electric propulsion system. The fossil fuel part is used to bring the plane at the desired altitude, while losing fuel weight in the process and continue less energy intensive flying and descending on battery power. 2020 is the target year to assess if larger scale e-flying is a realistic prospect in the first place. For small planes this has already been proven.

[] – Electric Aircraft Roadmap
[] – Siemens and Airbus sign long-term cooperation agreement in the field of Hybrid Electric Propulsion systems
[] – Airbus’ Urban Air Mobility Roadmap leads to an electric future

Read more…

Renewable energy in Europe 2017

EU-report from this year describing the state of renewable energy in Europe.

[] – Renewable energy in Europe 2017

OECD Renewable Electricity 2016 Breakdown

Hydro-power is still more than 50% of all installed renewable electricity.

[] – Renewables information: Overview 2017

Stanford – Global Road Map 100% Renewable Energy

We reported earlier about the Stanford report, claiming that a 100% renewable energy base is possible for the US or 138 other nations.

Here is the report itself plus some interesting graphs:

[] – Stanford report: 100% Renewable Energy For 139 Nations [pdf p201]
[deepresource] – Is a 100% Renewable Energy Base Possible?

Footprint 100% global renewable energy base: 1.7 million wind towers + 87k km2 solar panels (2 x Holland)

And the winner is… Tajikistan! Country ranking from 2015 renewable energy penetration in all energy sectors

French Oil Giant Total Into Renewable Electricity

French oil giant Total follows in the footsteps of that other European oil major Shell, in betting on the success of renewable energy. This is no doubt influenced by the radical choice for renewable energy by the European Union, that wants to get rid of fossil fuel in Europe by 2050.

[] – Oil Giant Total Sees Bright Future in Electricity
[] – Total commits to electric vehicle charging stations in France
[] – French oil giant Total expands into solar energy in Japan
[] – France’s Total buys stakes in solar power start-ups
[] – Total invests £800m in US solar power firm
[] – Could France’s Total reinvent the grid?
[] – French Oil Major Total Is Gung-Ho for Solar, Batteries and Grid 2.0
[] – French oil firm Total bets on renewable energy with near €1bn bid for battery maker Saft

Read more…

2050 – An Energetic Odyssee

Fascinating English-spoken video of Dutch origin [*], with graphics illustrating the energy policy of the European Union for 2050 (of which Britain will no longer be a part after Brexit). Core of solving the energy and climate problems are 25,000 10 MW offshore turbines that will provide the countries bordering the North Sea with 90% of its electricity needs and leaving ample additional capacity potential to provide the rest of Europe with energy as well, in the form of electricity or hydrogen.

[] – 25.000 Windturbines in Noordzee
[] – 2050 – Een Energieke Ontdekkingsreis

[*] – A production of IABR in cooperation with Ministerie van Economische Zaken, Van Oord, Shell, TenneT, Zeeland Seaports, European Climate Foundation, RWE, Natuur & Milieu, Havenbedrijf Rotterdam and Havenbedrijf Amsterdam e.o.

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