Giant batteries

http://www.popsci.com/technology/article/2010-04/giant-gravel-batteries-could-make-wind-power-consistent-energy-option

The unpredictability and non-uniformity of wind is one of the largest technical problems facing wind farms. A company in Britain thinks it has figured out how to use argon gas and 200ft barrels of gravel to store electricity in a high volume, low loss, low cost manner. If it works, the devices would capture excess energy in windy times for use when the skies are calm.

Their pilot project is only 23 feet tall. This is still too big for a house, but a large apartment block or shopping center could have some solar panels and small wind turbines hooked into something like this. They could also be useful in a smart grid set up accepting extra energy if a broken link causes a surge. Rather than cascading surges and blowouts, the batteries could absorb the extra energy and return it once the grid is stabilized.

Micro hydro?

With all this rain, we bought ourselves a rain barrel. For a few bucks at Ocean State Job Lot, we got a 150 gallon barrel and set it up in time for the latest deluge. It was full by noon the next day.

All the water flowing off our roof got me thinking about how much energy could be produced if you funneled it all through a turbine. It seems like it should be a lot (picture the energy involved in dropping a full 150 gallon barrel off of a two story building). My rough calculations for a 1000 square foot roof, two story building, with 50 inches of rain annually (Worcester county) is 1 3/4 kWh.

A Google search turned up some patent applications, but nothing concrete...

Protein sources

The Green Lantern at Slate just addressed a question that's been bugging me for a while now. How does tofu stack up against meat for environmental impact? Soy protein is better than animal protein in most regards, but there is a whole lot of processing involved in making tofu. How does that tilt the balance?

Rastogi references a Dutch study that ranked Dutch made tofu slightly worse than Dutch raised chicken. She then takes a stab at adjusting the results for the US and decides that US tofu is probably better than chicken, but not dramatically. The change is mostly because the dutch get beans from South America.

The Dutch study is worth a look, even if the results cannot be translated directly to the US. It covers every protein source from veggie patties, to cheese, to fish and back. A quick look at the graphs (I haven't read the whole thing) revealed to surprises to me. First, cheese is horrible in this regard. Second, lamb is the worst thing ever. Which is too bad, because I wanted lamb to be a earth friendlier alternative to beef. Ah, well, I guess I'll have to live with the guilt.

Eggs, nuts, chicken, tofu, and most fish are all about the same. Milk is a slightly better and local seafood is even better than milk. Their numbers also indicate that cutting out dairy reduces greenhouse gasses as much as going meatless. That must be mostly the cheese.

Keep in mind that this is a Dutch study and the focus is greenhouse gasses. So if, like me, your concern extends to other pollutants and effects, don't treat these numbers as gospel. However, I haven't seen anything else half as useful.

Super bugs

No, I'm not going to write about drug resistant TB and its friends. I'm talking about the microbes Craig Venter is going to make. He is talking about engineering microorganisms that can make biofuels from sunlight, air, and water.

I don't know too much about his plans, but I've written in the past that algal biofuels seem to be the only biofuel tech that makes sense on a large scale. Most other approaches compete with food production. I've heard that he is starting with marine algae so as to avoid conflict with fresh water needs.

I also know that Venter is not someone to bet against in this arena. As with sequencing the human genome, the science isn't in doubt here. The question is whether it will work at a useful scale. I hope he can do it and suspect he will. One of his moves (and this is no secret formula) is to use money to lure really smart and creative folks to his cause. He just hired a friend of mine away from our lab.

Another good TedTalk

Shai Agassi's talk at TED this February, presented his vision for how we could make electric cars feasible now and why it's the best way to go now. He's not the most amazing speaker, but there are quite a few good ideas in here.

The key idea of the whole thing, and the idea behind BetterPlace, is swapping batteries instead of charging them. If automated, it could be quicker than fueling up a gas car. It starts to make the electric car pretty appealing.

The rest of the talk is a rambling mix of tales of his attempts to get governments to buy into his vision and more reasons why we need to make the switch to electric. One bit I liked was his a recounted conversation with someone from the Israeli government in which he proposed turning some large tract of land into a solar farm that would power all the cars in the country. His point was that they'd not hesitate if that same piece of land held enough oil to run those cars for some number of years. The solar power would never run out. I really like that point of view for setting aside large tracts of land for solar.

Oh yeah!?

I'm not really the type to pipe up and get into an argument when people say things like "there's just not enough sunlight for solar to replace coal" or "I don't by organic because it's fertilized with manure". My instincts tell me that these statements are wrong, but I'll lose the argument every time because I don't have all the facts at my finger tips. I can do research later and refute everything, but it's like coming up with the perfect retort for that bully long after he's gone. The first example came up recently, and I let it go, but I figured this blog gives me a chance to set the record straight (to no one in particular).

Last year, Scientific American published an in-depth article explaining just how we could power the entire country on solar. Granted it would be a huge investment, but it would work. It involves building huge collectors in the southwest and building a new transmission network to get the power where it's needed. One of the problems was how to make solar energy available at night, most storage techniques are untested, expensive, lossy, or all of the above. They propose storing heat in salt domes or something.

Two recent developments will alleviate most of these problems. First, researchers at MIT figured out an efficient way to use solar energy to directly separate water into hydrogen and oxygen. Traditional electrolysis zaps water with a current to pull the molecules apart. This takes far more energy than can be recouped by burning the hydrogen. The new method is much more efficient. Second, Australian researchers figured out how to make fuel cells without platinum. That should reduce the cost of pulling the energy back out of the hydrogen.

Storing energy as hydrogen may also help the transmission issue. I don't know the numbers, but it could be more efficient to build a hydrogen infrastructure rather than transmitting electricity directly.

Biofuel Folly?

There has been a lot of hype around biofuels over the last year or two. Any sane person can see that corn based ethanol and soy or palm based biodiesel are just plain silly. Switchgrass based ethanol is definitely a step up from corn (if we can ever commercialize it). Crop based fuels have the additional problem that we have to use land that would otherwise produce food (or remain virgin forest in the case of sugar cane or palm) to get these meager energy increases. The land is more valueable in other uses.

So why are we still hearing about corn? Because it can be done today. Never mind that it's not much of an improvement over fossil fuels. There is a big lobby behind it and it gets results now, even if the results are not worth anything. Thankfully, we're starting to hear some vocal opposition to these fuels from some sensible folks.

Photovoltaics and concentrating solar arrays can produce 100 times the energy per acre of corn ethanol. The problem is energy storage. Fuels are just more effective than batteries at storing energy for long times.

It seems algal biodiesel is the clear winner for biofuels. The energy produced per acre is much higher than even cellulosic ethanol, it uses much less water, and can be produced in locations with little or no agricultural value.

Hybrid selection

I heard an interview with a car salesman who talked about people coming into showrooms asking about hybrids, but leaving with a conventional vehicle when they learn about the price difference. This seems to be the conventional wisdom: consumers want to feel good about what they buy as long as it doesn't cost much extra.

I'm not disagreeing with this in general, I think it's true to some degree. But I believe it's an oversimplification and a cop out for producers. We bought 2 new cars in the last year. (I know, not very green of us.) Sure enough, both times we went in looking at hybrids.

The first time we went shopping, we were looking for a vehicle that could hold us, 1-2 kids and some number of dogs comfortably. We loved our Matrix, but we had out grown it and were about to drive across the country. We looked at the Prius, but it didn't offer much over the matrix in ability to get car seats in. We also looked at the Highlander hybrid, but it's much bigger than we needed. We settled on the mazda5. It's a cool little car. Not much bigger than the Matrix (a foot longer and an inch narrower), it has 3 rows of seats and sliding rear doors. Exactly the car we needed and nobody else makes anything close to it. Forget about finding anything that size in a hybrid.

Once we got here and settled, it became clear that we needed a commuter car. The mazda gets much better mileage than any minivan (because it's much smaller), but not what I wanted to commute in. The Prius was higher on the list this time, but still, a much bigger car than we wanted. We went to a Honda dealer to look at the civic hybrid, but this is also a large vehicle these days. We left with a Fit. This is a great little car and still gets high 30s for highway mileage. Again, show me a small hybrid hatchback and I'd have bought it.

The problem is not that people won't spend a premium to get a hybrid. The problem is that people won't spend a premium to get a car they don't like. The Prius points to this. People who really care about fuel economy tend to think it's a cool design and it flew out of the dealerships.

A lot of our peers (young folks starting families) care about the environment but also don't care for traditional concepts of what a car should do. I consider a sedan a waste of space. With a smaller foot print, a hatchback can hold more stuff. Look at the newer car models of the last decade that aren't SUVs. When we bought our toyota echo 8 years ago, the small hatchbacks for sale were: the Golf, the Focus, and maybe the PT cruiser was out already. Now VW added the Rabbit, the Echo has been replaced by the Yaris which has a 3-door model, the scion comes in 2 flavors, the Aveo, the Aero (Suzuki), Kia has one, the Fit, the versa, the Matrix, and the crossover vehicle is huge now. The only hatchback hybrid is the Prius and it's aimed at the full size market.

Make a small hybrid hatchback and it will sell. Hell, Toyota has a Mazda5 size minivan in Japan. Put synergy in there and ship them to the US. They'll sell.

Compact fluorescent bulbs (CFLs) use much less energy than incandescent bulbs to make a similar amount of light. These bulbs are touted as an easy way to reduce energy consumption and quickly put a dent in greenhouse gas emissions. They have some well known problems: they warm up slowly, give lower quality light, are more expensive, and contain mercury. None of these are show stoppers. The latest bulbs warm up in seconds and they are getting cheaper. They also last longer. Recycling bulbs properly (mostly) mitigates the dangers of the mercury. These are all reasonable sacrifices for saving the planet.

Many governments are considering laws to ban incandescent bulbs. This is just plain ridiculous. While well intentioned, this is not the way to go about solving our problems. Even if CFLs were the perfect replacement for incandescents, it would be a questionable move. However the issue is not that clear cut. When you look at it more closely.

First, the higher cost corresponds to the increased resources and energy required to make these bulbs. Second, people are not recycling these bulbs consistently. I just recently found out that I needed to. (Of course, none have burnt out since then). Third, these bulbs are more sensitive to conditions and are not well suited to some uses (outdoor, refrigerators, ...). Again, I'm not sure these reasons are show stoppers either, but they certainly suggest that an outright ban on incandescents might be unwise.

The argument is also made that CFL bulbs must be left on continuously to achieve the lifetimes touted by manufacturers. I'm not sure I buy this for two reasons. First, I have seen no data and the argument seems to only appear when people are making the case for keeping incandescents. Second, I'd bet incandescents have the same problem.

Don't get me wrong. I think incandescent bulbs should get phased out. However, I think in the long term, LEDs will provide the answer. Even more efficient and longer lasting than CFLs, they also give a better quality of light. I want to build one of these.

For now, though, I don't have an answer. I'll try to do some research on CFLs before we move into the new place. I don't want to go buy a house full of CFLs to find out I wasted my money, but I don't want to waste energy on incandescents because I bought into the establishment FUD. I'll look into it and post more later.

Factory Heating

A couple weeks ago, Living on Earth covered the ongoing restoration and reuse of an enormous old factory building in Lawrence, MA. Sounds like Lawrence faced, on a larger scale, a similar situation to the one Hopedale is in now. The old mill in Lawrence is being, re-used as office space. I worked in a restored red-brick mill in Cambridge a few years back. It was a really nice space to be in. These buildings generally have large windows and lots of red brick. In the hands of a good architect, it's hard to go wrong aesthetically.

What's important in restoring these buildings is to try to preserve the sense of community that still exists in these towns. Turning the Draper building into office space just moves Hopedale closer to being another suburb of Boston, albeit with nice architecture. To be fair, architecture can give life to an otherwise boring place, but the town has much more going for them in terms of history and local culture.

The Lawrence mill is having a huge geothermal heating and cooling system installed. This is an extremely efficient way to climate control a space and efficiency is critical for a gigantic old building. The LOE coverage does not draw a clear line between this kind of geothermal installation and one that would actually generate electricity. he one in Lawrence still requires an electric pump to transfer the heat. The distinction is the same as between solar water heaters and photovoltaic solar panels. in both cases the former reduces overall energy costs, but does not produce usable power. They are also generally cheaper. When I was growing up in Texas, the electric company was advertising heat pumps, which I gathered were just smaller versions of what's going in at the Lawrence mill. I'm a bit surprised that such a system is still newsworthy.

Energy use should be significant portion of any plan to restore the Draper Building. Poorly implemented, it could be a huge energy hog. It's a large, old building. Done well, it could be an example of good design. I would argue for some sort of green certification. Maybe a green roof could be used to reduce heating/cooling costs. The dam that creates the Hopedale Pond is on one wall of the factory (it's an old mill), and could be used to power the pumps in a geothermal heating/cooling system.