Tag Archives: renewable

Story of methane

I thought of writing about methane. It is a curious molecule consisting of a single carbon atom surrounded by four hydrogen atoms around it which pretty strong bonds with the carbon atom. The entire molecule is relatively small and exists in gaseous form at room temperatures. It is naturally occurring and comes out of natural processes that involves anaerobic bacteria actions. It is a fuel that can be combusted to produce carbon dioxide and water vapour.

It also happens to be a greenhouse gas. Each methane molecule is thought to have 25 times more global warming potential than carbon dioxide. Natural gas is largely made up of it; hence it is a greenhouse gas by itself though combusting it will also produce carbon dioxide which itself is a greenhouse gas though with lower potential.

The focus on carbon emissions is a result of the recognition that we have spewed so much of this particular greenhouse into the atmosphere that it is having extreme effects on the global climate due to the warming potential. The world needs to move towards low-carbon and that means having activities that are emitting less carbon dioxide into the atmosphere. In general, fossil fuel based carbon holds the largest responsibility in anthropogenic carbon emissions.

Interestingly, you could produce methane through anaerobic biological process. And cows are known to release methane into the air because of the bacteria actions in their stomach. The dairy industry therefore becomes a rather larger emitter of greenhouse gas for this reason. That is where stuff gets a bit fuzzy when you’re counting global warming potential, anthropogenic emissions and so on.

So biomethane is the methane produced through anaerobic digestion of organic matter can be captured and used as a fuel. When combusted it likewise produces carbon dioxide and water. But this carbon dioxide belongs to the short carbon cycle due to its organic/plant heritage and hence is excused from what typical constitutes carbon emissions. Yet when biomethane leaks or is released into the air, the methane’s global warming potential is counted and the carbon-equivalent emissions actually forms part of the emissions from processes whenever biomethane is used. This ‘short cycle’ argument doesn’t seem to apply.

This may not seem very consistent and can potentially create a lot of confusion around the truly ‘green’ identity of biomethane. One could see how biomethane, or renewable natural gas as it is known in the US, is going to suffer from being conflated with fossil fuel natural gas.

Cheap renewables and surging bills

Even as we see the levellised cost of solar coming down, and increasing penetration of renewable energy, the electricity coming to us in our grids are increasing in prices. At least it seems to be so in Australia. There’s a lot of cost associated with the transmission and distribution infrastructure that needs to be recovered – partly because the growth of intermittent renewables mean that the grid infrastructure will have to be expanded.

But it is not just that; there’s also more padding required in the margins of electricity retailers because the intermittency results in even more volatile electricity prices in the wholesale market. That means that if the retailers are still providing fixed price tariffs and long contracts to customers, they will have to manage their risks by putting higher profit margins into the retail packages.

There is a huge price to pay by the society to eventually enjoy more renewable energy. If we don’t adapt to the intermittency through more adding more flexible generation leveraging on demand response and integrating EV recharging networks into the network operation optimisation (ie. Vehicle-to-Grid systems), we can only expect higher bills. We had better accelerate the transition or we’re soon losing the patience of energy consumers.

Primitive technology

Had a chat with a friend who used to be in the oil & gas industry; well at least along the value chain. He was also a bit on the old school side of things and he calls solar PV technology primitive because compared to the gas turbines whose efficiency is 60% when using combined cycle, the efficiency of converting solar energy into electricity is only 15-20%.

I was a bit surprised at that idea given that inputs in terms of the energy from the sun is free whereas you might need to calculate the energy cost from the drilling, piping, even liquefaction and then gasification of gas. Nevertheless, the point is that turbine technology has been widely adopted and used for many more decades than the solar panels. So a lot more money, time, resources have been invested into that those technology compared to renewables. That is simply fact.

Yet if you consider which technology has more room for progress and can move us to a future that we want to live in, the answer is just as clear. The problem again, with the economic analysis undertaken is that they are all based on individuals considering Ceteris Paribus everywhere else. The energy transition, decarbonisation is more than just that an individual decision and it was never meant to be worthwhile done alone. It was something to be coordinated, actions taken together. Which is why we cannot allow all of these technologies like solar, wind, EVs, hydrogen to be as primitive as they are.

Making the transition II

Transition means being in an in-between state, crossing over to something which is supposed to be perhaps a less temporary state. The challenge, however, is that one can get stuck in transit. Natural gas as a fuel risk being in that state because it wasn’t really adopted fast enough as a transition fuel. And now renewable electricity from solar and wind has more or less leapfrog it in terms of cost advantage. Once battery or other energy storage technology moves along the cost curve and decline sufficiently, natural gas might even be bypassed.

So the world is in a somewhat confused state. When is it right to use gas? What should be counted as alternatives for decarbonisation? In any case, gas prices are spiking now so what does it mean? Should that mean we move forward into more renewables which might even be more expensive? Or we move backward into coal?

These decisions are not meant to be made in categorically; because the entire system needs to be considered. And what is at the margin in terms of choice needs to be clearly identified. If the additional unit of power that satisfies both energy security and the quantity demanded can be obtained through renewables, it should be used. Of course if that is not available, one might have to step back into more carbon-intensive processes. Availability can also be based on budget.

Natural gas itself, needs to be displaced by greener fuels without threatening the underlying combustion technologies that underpin the gas turbines. But that is perhaps for another day.

Solar as Future of Energy

The Economist ran a couple of stories about Solar Energy in the latest issue (16 April 2016); mainly touting the trends the industry has been facing in the recent years:

  1. Falling cost of panels
  2. Increasing interest, attention and commitment (in the form of Feed-in Tariffs)
  3. Falling levels of subsidy support and FiTs
  4. Increased avenues of financing and ambitious solar farm projects

Quite a couple of bottlenecks to the growth of solar still awaits solutions; and in the recent years, competition in this industry will be shifting into solving some of these problems holding back the development of solar energy.

  1. Land intensity of PV solar farms (need to improve efficiency and quality of PV cells) – land is an issue because of potential competition with arable land (plants need sunshine too) in certain places
  2. Intermittency of Solar power (a large dark cloud moving over a PV farm by can reduce generation significantly and abruptly – need for energy storage and some sort of balancing mechanism)
  3. Grid curtailment issues; inability of the grid to take in the power generated when at the peak generation capacity (especially with wind power thrown into the vicinity).

As a result, I believe these issues are going to drive the growth of this few industries/businesses:

  1. Data analytics combining weather/cloud forecasting with energy storage smart systems to optimise the operations of large scale solar farms
  2. Market platforms that helps with cost-balancing and electricity trading in order to smoothen demand and supply fluctuations from solar/wind power
  3. Improvements in both energy storage technologies as well as PV cell technologies.
  4. Further financial innovation in financing solar power deployments – including leasing of panels, leasing of rooftop space, usage-fee-purchase model, etc.