Energy use and GDP

Per capita electricity use / day
USA : 40 units (of which 36% is residential)
EU : 20 units (35% is residential)
China : 7 units (15% is residential
India : 2.5 units (!) (20% is residential)
World : 8 units (27% is residential)

Take a look at this very interesting graph..  
A good straight-line fit gives us a GDP of 40 cents for every unit of energy (total, not just electricity) consumed.  I know there are some implicit, non causal relationships, but this is a wonderful number to remember.. say for India to reach a per capita GDP of $10000, the annual per capita energy use could be close to 25000 units. Another way of looking at it (a Nobel winning Stanford Prof says this): For (roughly) every dollar spent on energy, you typically generate 4 dollars of GDP.  Quite remarkably, this number is more or less the same across all type of economies including for the big bad US of A. Americans account for 25% of the world's energy consumption and account for 29% of its GDP. In other words, there are no shortcuts, at least so far.


India better be building one nuclear reactor every month for the next 20 years ?

Daily energy use of the world : 360 billion units
Global power consumption : 15 Tera watts
Guy with a plan:  http://www.stanford.edu/group/efmh/jacobson/Articles/I/susenergy2030.html

Some numbers related to Energy

Energy Densities (Amount of energy released when the given substance completely combusts with oxygen at standard atmospheric conditions)

Coal :          10-24 MJ/kg
Wood :        14 MJ/kg

Gasoline*:    44.2 MJ/kg (31.7 MJ/litre)
Natural gas: 53.9 MJ/kg (0.038 MJ/litre)
LNG          : 53.9 MJ/kg (22 MJ/litre)
Propane     : 50 MJ/kg (25 MJ/litre)
Biogas       : 28 MJ/kg  (7 MJ/litre)
Hydrogen : 119 MJ/kg (8.1 MJ/litre)

Lead-acid batteries : 0.125 MJ/kg
Li-Ion batteries : 0.432 MJ/kg
Alkaline batteries : 0.594 MJ/kg

* Diesel and Kerosene are within 3% of this number

Let's switch to convenient energy units i.e.,  1 unit = 1 kilo watt - hour = 3.6 MJ

So a kg of coal contains roughly 6 units of energy and a litre of Gasoline contains about 8.75 units of energy.

Note that the energy density of the best possible battery is about 100 times less than that of an equivalent mass of gasoline. Of course, electrical energy conversion is much more efficient than thermal energy conversion, but this fact is only going to buy us a factor of 2. In addition to being heavy,  battery electrodes are quite expensive as well. Even though things are improving, you should get a sense of what electric cars are up against.

If you assume that gasoline costs $3.50 / gallon, the price you are paying per unit of energy content comes to 11 cents. This is quite interesting because we pay around 10 cents / unit of residential electricity.

Cost / unit of energy content  (at wholesale prices) :

Coal  :  0.4 cents / unit
Natural gas : 1.5 cents / unit
Crude oil : 5 cents / unit

Note that so far, we've been just talking about energy content in fuels and haven't considered conversion losses. If we take everything into account and go by the wikipedia definition:

Levelized Energy Cost (LEC) is an economic assessment of the cost of the energy-generating system including all the costs over its lifetime: initial investment, operations and maintenance, cost of fuel and cost of capital,  this is what we get

 The chart shows cost / Mega watt - hr, so divide the last column (which is in dollars) by 1000 to get cost / unit of electricity. So according to this chart, conventional sources cost less than 10 cents / unit and land-based wind energy is competitive. Solar energy continues to be off the charts expensive even with all the recent advances.

Coal and natural gas based energy is dirt cheap and the big 3 energy consumers (USA, China and India) have enough reserves to last out this century at least as far as electricity use is concerned. Transportation fuel may be a bit more complicated with the approach of peak oil (and such), but I think gas to liquid technologies will come to the fore. Note that if more stringent emission restrictions are brought in on fossil fuels, wind energy has a good chance to be very viable and Solar can become borderline competitive.

Overall,  the cost of energy continues to be amazingly low considering the fact that the best cyclist in the planet can only give you 0.3 units of energy over an hour and animal labor isn't that much different. Yes! I compared the present situation with the stone age to make you feel better!

Cost of Green energy?

Being quite curious about what Sarah Palin had to say at the India today conclave, I came across this nugget from her speech : "A recent British study shows that for every 'green job' created, nearly four jobs were lost elsewhere in the economy due to lack of affordable energy!". Now, especially given the person who said it, it is quite easy to ridicule the statement, but I looked it up. Quite clearly, Palin oversimplified the argument (and messed it up), but the actual study did conclude that the costs associated with higher energy prices and government subsidies outstripped job creation by a factor of 3.7. So they were looking at it purely from a jobs/economic perspective, and in the near-term (and not the impact on the environment). This is not just in isolation.. studies in Holland, Germany and Spain have also indicated similar (though not as drastic) results and it has prompted some governments to cut back on subsidies.

These kinds of studies are always open to severe criticism. It is not even easy to nail down a number for the cost of wind energy. Direct generation costs (cost per unit of energy generated by a wind turbine) are easier to estimate, but if you consider the plethora of subsidies and tax-breaks, it gets a lot more muddled (there is also this small matter of effectively distributing it to the customer). If I have to pick a number, I'd say perhaps 6c/kW-hr (not including subsidies), which at least about 30-40% more than conventional sources like coal and natural gas. The good news is that wind energy used to cost many times more about 25 years ago, but the bad news is that the rate of cost reduction has tapered off in recent years.

Now, if wind energy were completely reliable and we had a good transmission/distribution model and the quantitative effects of man made carbon emissions on the atmosphere can be determined  and we had a better idea of when we would run out of oil, then paying the extra 30-40% would be pretty easy.  Fact is, there is no guarantee that ANY of these issues will be resolved in the near future, so it will just boil down to cold numbers: Cost of wind energy has to go down (along with the % of subsidies) by quite a bit. With the discovery of all kinds of shale gas and assorted resources, in my opinion, fossil fuels will be too useful to ignore because they will continue to be cheap in the near future.  With new developments in Fischer-Tropsch techniques (coal to gas and gas to liquid conversion), alternative energy will find the going a bit difficult unless the hammer comes down on pollution (good luck with that in the near future). Incorporating Carbon capture technologies in fossil fuel based plants will increase costs considerably. Till then we will hear more and more Palin-type rumblings and they won't be completely unjustified.

ps: If you are thinking about bias, please consider the fact that part of my research is on wind turbines.

Monitoring energy use... in great detail

This post was spurred by a couple of nice developments - one at home and one at work.

First, while paying my electricity bill on-line, I noticed a link to "usage statistics". I clicked on it and found that I could monitor my energy usage monthly/weekly/daily and even by the hour. This is how a sample day looked like:

I think that it is super-cool. About as important a development as any and as I said on Facebook, this is truly deserving of the smart prefix.  Nothing helps a cause more than affixing good hard numbers to stuff ($ values are even better). That said, we gotta go easy on using my HDTV and microwave.

I work with some kids in the computer science department and the last time I went for a meeting there, I noticed cell phone sized devices attached to each power-outlet and the computers and other paraphernalia were connected to these. It appears that some student is running this thing using which you can monitor how your energy gets used - in a way that is way more detailed than my home usage. Take a look at this awesomeness:

powernet.stanford.edu is where its at - If you set up an account with them, you can monitor every power-outlet you use and break it down in great detail. True to form, the nerds (sorry guys) that I work with even had a powernet device monitoring the energy usage of another powernet device.

I was thinking about breaking down the energy usage in my laptop and that got me going on how incredible it would be if we were able to do this on our cars - I'd be interested in knowing how much energy I lose in applying brakes, stepping on the gas for no reason, air conditioning, idling, etc. I'd pay to be able to graph it. Think Prius times 10 levels of greatness.

Seriously though, there is no better innovation in energy efficiency than cutting down wastage. Monitoring energy use is the first step.

Edit: People will protest anything http://www.montereyherald.com/local/ci_17545753?nclick_check=1

Ecological footprint and sustainability

The impact of mankind's activities on our planet is unquestionably one of the major issues in the 21st century. While it most definitely is a highly subjective topic and everybody has an opinion that ranks somewhere on a scale spanned on either end by Gore and yee-haw, I doubt anyone can argue against the fact that natural resources are finite and that we are (at the very least) using up a non-negligible fraction. Given that a significant portion of the world's population is poor and several developing countries are growing very rapidly, I often wonder about sustainability.

I came across this rather interesting report  put together by a bunch of organizations including the OECD and WWF. Using various metrics of carbon footprint, grazing land, used forest areas, fishing, cropland and built-up areas, the report gives numbers related to the ecological footprint of various nations and the world. Paraphrasing from the report "Ecological Footprint (which represents demand for resources) and regenerative capacity (which represents the availability of resources) are expressed in units called global hectares (gha), with 1gha representing the productive capacity of 1 hectare of land at world average productivity." In essence, it is use vs availability. Obviously the metrics are somewhat subjective and open to criticism, but not too unreasonable in my opinion.

With some help from the good wife, I was able to get  data from the report and correlate them with per-capita income (adjusted for purchasing power parity, data from UNHD web-site) and came up with a couple of graphs. I have just considered countries with populations of more than 30 million to avoid noise.

Here is Graph 1:

I think the straight line fit is pretty cool. As expected, we have low and middle income African and Asian countries consuming less than the global average and good ol' uncle Sam going to work at the other end of the spectrum. Now, in about 20 years, China is expected to grow almost three-fold and overtake the US as the largest economy and India won't be too far behind. These countries will constitute about half the world's population in that time-frame and will be moving north-east on that graph, doubling the global average consumption by themselves in no time.. oh.. and there will be the little matter of about 500 million people in equally hot Brazil and Russia.

So how about sustainability? Here is Graph 2 (again, countries of pop. > 30 million, with the ratio of "available" to "used" hectares. So, a ratio of less than 1 is bad. Note that this ratio can be less than 1.0 because much like over-drawing from your bank account, you just don't allow regeneration to take place at its natural pace.

Not too unexpectedly, it shows that, as global citizens, we're using up more (50%) than what the planet can regenerate... and this is just in 2010. South Korea and Japan are in scary territory and India and China aren't looking very good given they're expected to grow multiple times.

With better energy sources, more productivity (in developing countries) and change in consumption practices (in developed countries) etc., the outlook can be more positive, but this is nevertheless a very critical issue and needs more serious characterization and attention. Sustainability is becoming a major issue and will soon (if not already) start stifling growth in many developing countries. Herein lies the grandest challenge of all for the two emerging Asian giants.