Energian tuotanto, kenttägeneraattorit ja muut


Energy demands from developing countries are going to grow by about 10 per cent between now and 2040, according to the US Energy Information Administration. By that year, they will be using 65 per cent of the world’s total energy supply.

But although new renewable energy technology can be adopted quickly, the basic energy infrastructure in the developing world is lagging behind. As a result, energy supplies are nowhere near as reliable. And that’s a problem. “In some places we have hospitals that have 12 hours of blackouts a day,” says Enass Abo-Hamed, chief executive and co-founder of hydrogen storage startup H2GO.

If electricity could be stored on-site for when it is needed, outages would be far less frequent. But the cost of existing battery technology is prohibitive. Abo-Hamed and her colleagues are working on an innovative way of storing hydrogen gas that can be burned in fuel cells. The system uses nanomaterials to create a partially flexible sponge that is able to trap hydrogen atoms in its pores. The gas can later be released by heating the structure.

“Once you reach the required temperature, the structure gets distorted and releases the hydrogen,” says Abo-Hamed. It’s a bit like pushing corks out of bottles. But first, you have to get hydrogen. From splitting water molecules (H2O) into hydrogen and oxygen. H2GO will use a water electrolyser for this process. Abo-Hamed says that, based on their calculations, a medium to large hospital in sub-Saharan Africa, for example, would need about 50 litres of water per hour. About 80 to 90 per cent of this supply is returned after the hydrogen is burned to make power, and can therefore be used again.

The H2GO team is now working on developing a cheaper material that mimics the mechanical behaviour of their prototype, so that the technology might be made affordable to buyers in developing countries. Leaving aside hydrogen-based solutions, the vast proportion of the world’s electricity is generated in more conventional ways. And many distributers simply want cheaper and more reliable ways of storing it.
But Chiang has other ideas, too. He’s developing a sulphur-based flow battery in which ions flow across a membrane between a sulphur-containing anode and a cathode. When discharging energy, ion flow is enabled by the oxidisation of sulphur compounds in the anode. “The beauty of sulphur is it’s produced as a by-product of refining,” he says.

“Currently, the stockpiles we have of sulphur due to natural oil and gas refining are enormous in terms of the storage we could potentially generate from them.” A separate start-up founded by Chiang, Baseload Renewables, is developing this sulphur battery technology with the hope that it might be used in developing countries to store energy for days or even months. That way, a basic energy supply could be provided to local electricity networks. Baseload Renewables has just been selected to receive investment from MIT accelerator The Engine.


When hurricane Irma threatened Florida, I was not worried about the food in my fridge going bad or scrambling to buy ice, because I had an inverter in my garage hooked up to a 12 volt battery made up of two golf cart batteries. With new batteries, this setup would provide around 2 kWh of backup power, although I’m currently using 4 year old batteries that had previously seen 400 cycles of use in an electric vehicle, so the actual performance is closer to 0.6 kWh (600 Watt/Hours).

When Irma hit, we lost power at 1am on Monday were without power until 5pm on Wednesday, or around 64 hours. However, I only ran my backup system for 31 of those 64 hours. I first hooked the system up around 1pm on Monday, and ran it until 10pm. I shut it down overnight when I was sleeping and ran it around 11 hours each on Tuesday and Wednesday during the day. My fridge was easily able to keep things frozen/cold overnight and “catch up” during the days (I had loaded the freezer up with a lot of frozen water, and the fridge with a lot of chilled water well before our outage occurred).

Over the 31 hours I ran the system, we averaged 190 watts of draw per hour (or 5890 watt / hours or 5.89 kWh total), which is significantly larger than the 0.6 kWh the golf cart batteries could provide alone. This draw was primarily from our fridge, although we also used 20-50 watts of power to keep our DSL wifi-router running and charge personal electronics, as well as running the power hungry microwave for a few minutes at a time.

To augment the stored power in the golf cart batteries, I wired them in parallel with the 12 volt accessory battery on my electric truck (which has a 20-22 kWh battery pack). By leaving the ignition of my truck turned on, I enabled my 500 watt DC2DC converter which continuously charges the 12v accessory pack from the main (LiIon) battery pack. Because the 500 watt DC2DC converter was providing well more than the 190 watt average draw, the system worked well.

The golf cart batteries acted as a “buffer”, providing extra power to the (2000 watt) inverter if needed. [For example, when I used our 1300 watt microwave to heat up food for 5 minutes here and there.] And the golf cart batteries were topped up by the 12 volt system on the truck, ultimately powered by the main traction pack.

One big advantage is that the system is nearly silent, generating only a slight hum from a fan in the inverter that becomes inaudible as you walk away from it. It also has no danger of producing deadly carbon monoxide, which has already killed several people in Orlando due to mis-using gas burning generators.


Hirmumyrskyn kestävä tuulimylly, Japanista.

While wind energy is rapidly increasing its market share across the world, wind turbines are not able to be constructed everywhere that they might be needed. A perfect example of this is Japan, where a traditional wind turbine would get damaged by typhoons. After the Fukushima disaster, though, one Japanese engineer committed himself to building a turbine specifically for Japan that can operate just fine within hurricane-force winds. (YouTube, embedded below.)

The “typhoon turbine” as it is known works via the Magnus effect, where a spinning object directs air around it faster on one side than on the other. This turbine uses three Magnus effect-driven cylinders with a blade on each one, which allows the turbine to harvest energy no matter how high the wind speeds are. The problem with hurricanes and typhoons isn’t just the wind, but also what the wind blows around. While there is no mention of its impact resistance it certainly looks like it has been built as robustly as possible.

Hopefully this turbine is able to catch on in Japan so they can reduce their reliance on other types of energy. Wind energy has been getting incredibly popular lately, including among hikers who carry a portable wind generator, and even among people with just a few pieces of scrap material.


3 kertaa enemmän tuuli energiaa merellä kuin maanpäällä.

The world’s first offshore wind farm employing floating turbines is taking shape 25 kilometers off the Scottish coast and expected to begin operating by the end of this year. New research by atmospheric scientists at the Carnegie Institution for Science in Stanford, Calif. suggests that the ultimate destination for such floating wind farms could be hundreds of kilometers out in the open ocean. The simulations, published today in the Proceedings of the National Academy of Sciences, show that winds over the open ocean have far greater staying power than those over land.

Wind power generation is obviously contingent on how fast and how often winds blow. But only over the past decade have scientists and wind farm developers recognized that the winds measured prior to erecting turbines may not endure. For one thing, dense arrays of wind turbines act as a drag on the wind, depleting local or even regional wind resources.

It is now generally accepted that drag from wind turbines in the boundary layer (where the atmosphere interacts with Earth's surface) limits the kinetic energy that large land-based wind farms can extract to about 1.5 megawatts per square kilometer (MW/km2). "If your average turbine extracts 2-6 MW, you really need to space those turbines 2-3 kilometers apart because the atmosphere just doesn’t give you more kinetic energy to extract,” says Carnegie postdoctoral researcher Anna Possner.

What Possner and climate scientist Ken Caldeira reveal today is that the atmosphere is more generous out in the open ocean. There, they estimate, wind farms could be packed more tightly, because energy should flow down from above the boundary layer to quickly restore winds depleted by wind turbine rotors. In some regions, such as the North Atlantic, the simulations suggest that large wind farms can extract 6 MW/km2 or more.


The high cost of batteries still prevents them from being used to store renewable energy for times when the wind dies down or there’s no sun. Pumped hydroelectric storage is the cheapest known energy-storage technology today, but is limited by geography.

With a new battery, researchers at MIT say they have found the sweet spot for energy storage. The energy-dense battery could be the first to compete with the installed cost of pumped hydro and compressed-air storage, which cost around $100 per kilowatt-hour of energy stored. Scaled-up versions of the new battery could store electricity for a fifth of that, at $20/kWh. By comparison, Tesla claims its Gigafactory can produce batteries for around $125/kWh.

The new battery might even have what it takes to replace fossil fuel “peaker” plants that can quickly inject power into the grid at high demand times. To compete with peaker plants, we need immense batteries that store energy from wind and solar for multiple days, even months, at an installed cost of around $50/kWh.

The device, reported in the journal Joule, is a type of flow battery, in which both the anode and cathode are liquid electrolytes. The anode in this case is sulfur dissolved in water, while the cathode is an aerated liquid salt solution that takes up and releases oxygen.

Lithium ions move between the electrolytes, and the salt solution at the cathode takes up or releases oxygen to balance the charge. During discharge, it takes up oxygen and the anode ejects electrons into an external circuit. When the oxygen is released, electrons go back to the anode, recharging the battery.


For the first time a group of scientists has captured close-up images of mysterious finger-like growths known as dendrites that can lead to short circuits and fires in the lithium-ion batteries that power hordes of smartphones, laptops and other gadgetries.

By using cryo-electron microscopy (cryo-EM), researchers from Stanford University and the US National Accelerator Laboratory have revealed that the lithium metal dendrites are long six-sided crystals. Their study was published in Science on Thursday.

The growths can spark battery fires by causing a short circuit if they pierce through the separator, a membrane placed in between the cathode and anode. The resulting surge of current can lead to thermal runaway, whereby the increased heat coupled with flammable electrolyte fluid spark fires.



Despite significant addition to power generation and transmission capacities in recent years, India still faces an energy deficit of 2.1% and about 20,000 villages are off-grid. Moreover, electricity supply to urban and rural India is still unreliable. As a result, diesel generators are widely used for decentralized power generation. These generators (Figure 1, top), although inexpensive, are inefficient and pose great environmental and health risks.

This is why the National Chemistry Laboratory (NCL) in India, along with two other labs in the Council of Scientific and Industrial Research (CSIR), the Central Electrochemical Research Institute (CECRI), and the National Physical Laboratory (NPL), are investigating cleaner, cost-effective, and more dependable technology for powering telecom towers and eventually buildings.

A promising answer to the cost and pollution conundrum can be found in proton exchange membrane fuel cells (PEM fuel cells or PEMFCs, shown in Figure 1, bottom), which are being phased into many applications as replacements for older power technology. Thanks to their small carbon footprints, low decibel levels, fuel compatibility, and excellent complementarity with other renewable energy options, they have potential for use in transportation, residential buildings and offices, and certain industrial sectors. PEM fuel cell systems have an overall efficiency exceeding 30% (compared to 22-25% for diesel generators), and when run on pure hydrogen, their only emission is water vapor.


By 31 December, a half-dozen 1-megawatt lithium-ion batteries could be in place, helping to support Puerto Rico’s electric power grid, which was almost entirely destroyed by Hurricane Maria.

Independent power producer AES is working with the Puerto Rico Electric Power Authority (PREPA) to site and deploy the batteries. Most likely, says Chris Shelton, chief technology officer of the Virginia-based company, the batteries—which AES is donating—will support the still-fragile grid by enhancing both power quality and grid stability.

“We are not looking for commercial applications,” Shelton says. “We are focused on putting them to work to help.”


Plans to modernize Puerto Rico’s power grid likely will include an array of fixes such as stronger electric poles, microgrids, and more renewable energy. The plan, expected to be released later this month, will also focus on reducing the island’s reliance on transmission lines that cross its mountainous interior. These proved to be a weak link when Hurricane Maria struck in September.

Puerto Rico’s electric power authority, PREPA, is writing the plan along with the New York Power Authority (NYPA), the Long Island Power Authority, ConEd, Edison International, the Electric Power Research Institute, and the Smart Electric Power Alliance.

The plan will offer details based on a request made by Gov. Ricardo Rosselló in November for $94 billion in federal aid to rebuild the island. Around $17 billion of that would be earmarked for the electric power system, which was largely destroyed by the storm.

Indeed, efforts under way since 2006 by Florida Power & Light offer a glimpse into one aspect of Puerto Rico’s anticipated grid hardening. Over the past 11 years, the Florida utility has spent nearly $3 billion to upgrade poles, harden substations, and deploy smart grid technology.

As a result, the utility reported that none of its hardened transmission structures was lost during Irma. All of its substations were up and running within a day after the storm. And although the utility lost around 2,500 poles (roughly 0.2 percent of its 1.2 million), that was a pittance compared with the loss of around 12,000 poles it suffered during Hurricane Wilma in 2005.

Poles are important, but are likely to be just one part of the modernization plan. Quiniones says that other elements likely will include standardized voltages across the distribution system, flood walls to protect critical infrastructure, and bundled conductors to improve transmission line efficiency.

In addition, the plan will call for increased use of renewable energy, microgrids, and distributed energy resources.

“We want them to think about a decentralized, cleaner grid,” Quiniones says. The upgraded system will be less reliant on moving power over mountains that separate the south side of the island—home to the bulk of generating assets—to load centers on the north.

The restoration plan will combine “good, sound engineering principles” with a nod to a more “decentralized, distributed grid,” Quiniones says. What’s more, it “has to be led by PREPA.”