A rethink of the grid design to shape our energy future

July 03, 2019

This article was first published in The Mint. You can read the original at this link.

Plants use photons from sunlight as sources of energy to create chemical bonds between molecules of carbon dioxide and water. This process, called photosynthesis, is how they create carbon-based stores of energy that they use to grow. When we burn plant matter, this energy gets released in the form of light and heat energy. Plants are, therefore, the batteries of the natural world, capturing energy from the sun and storing it in a stable form that can be transported from place to place and burnt to release the energy trapped within.

When humans harnessed fire, they learned to generate energy at will. This was a turning point in our evolution, and arguably the one scientific discovery to which every subsequent technological advancement of the species can be traced. It would not be an exaggeration to say that it was our ability to harness fire that set us firmly and irreversibly on the path to civilization.

The easiest way to release energy from our biological batteries is to burn them, a process that along with heat and light also releases carbon dioxide. The fact that fires generate carbon dioxide hasn’t ever been a problem as we’ve always had plants aplenty to convert it back into stored energy. However, ever since the Industrial Revolution, to meet the rising demands of our increasingly technology-dependent society, we have dramatically increased the amount of fossil fuels that we consume—so much so that the volume of carbon dioxide that we now generate has begun to exceed the capacity of our planetary ecosystem to re-absorb the gas.

The economics of modern electricity requires huge power plants to be established at remote locations and be connected to our homes and offices through the grid, a network of transmission and distribution lines that ensures availability of electricity in our power sockets whenever we need it. This centralized model doesn’t contemplate storing energy. Instead it calls for 24/7 power generation, varying the amount of energy generated only by season and time of day based on the anticipated load. In other words, unlike in the past when we burnt firewood only when we needed heat or light, today we are burning plant matter throughout the day and night to generate the electricity we need. If we are to have any hope of reducing our dependence on fossil fuels, we’ll need to find an alternative model.

We already have the technology to do what plants do, capture energy from the sun and convert it into a usable format. In recent years, we’ve become much more efficient at doing this, so much so that the economics of renewables has reached the point where mini solar plants are cost-effective enough to often be the preferred solution for extending electricity supply out into remote areas. Similarly, shrinking capital costs have made urban high-rises a viable location for rooftop solar installations, offering city dwellers the opportunity to economically generate their own power for the first time. We are finally able to capture energy directly from the sun and use it without needing plants as intermediaries.

The problem with this is that the sun doesn’t shine all the time. This means that if we’re going to increase our dependence on solar energy, we will need to find a way to store the energy we generate so that we can use it even when the sun is on the other side of the planet, or behind a cloud.

In India, most urban households already use uninterrupted power supply units to supplement the intermittent power supplied by our energy distribution companies. All I am suggesting is that we reverse the priority of these backup power units so that the stored energy in our batteries becomes our primary source of power, with the energy from our power generation installations being used to recharge our batteries when they get depleted.

If we go down this path, we will need to give some thought to where this storage should ideally be located, in our homes, at the nearest substation, or elsewhere. We will also need to develop innovative policies to incentivise the reorganisation of priorities that this will entail. Finally, though we’ve begun to see battery costs come down, we will need to ramp up production so that economies of scale allow the fall in cost of batteries to mirror the trend we’ve seen with the cost of solar panels so that we can achieve the level of cost efficiency that this sort of a solution demands.

One downside to all this is that batteries made using current manufacturing techniques are not the most environment-friendly products. They require high temperatures and result in the release of toxic by-products. It’s been estimated that building a battery for an electric car generates the waste equivalent of 20 tonnes of carbon dioxide, as much as would have been produced had 10,000 litres of petrol been burned. We need to find ways to build environment-friendly batteries with a low carbon footprint.

There are many people working on finding a solution to this problem. For instance, Angie Belcher from the Massachusetts Institute of Technology has been working on using viruses to grow biological batteries at room temperature and without harmful by-products. If she is successful, her batteries will be able to take any shape, allowing [[Electric Vehicle]] companies to build them into the dashboard of a car, or interior designers to make them part of the furniture. We will need innovative technologies such as these if we are to have any hope of positively shaping our energy future.