A duck as the biggest challenge for solar power

This is the time for alternatives
With the rapid advance of affordable, renewable forms of energy such as wind and solar power, the energy playing field is changing dramatically. Previously, energy was generated exclusively at a few central points around the country. Coal-fired power plants were built in remote locations where they caused little disruption. From there, the generated power was transported with thick cables to households and businesses. Simple, efficient and minimally inconvenient for society.

But those coal-fired power plants have a drawback: they are extremely pollutive. Coal contains toxic substances such as nitrogen dioxide, sulfur dioxide and mercury (the chemical element, not that of kwek and kwak). When coal is burned, these substances end up in the air and our drinking water. This results in lung problems, cardiovascular disease, brain damage and eventually premature death. Furthermore, working conditions in coal mines are often particularly harrowing and the greenhouse gas emissions from coal-fired power plants have a devastating impact on the environment.

It is time for change and fortunately today, there are affordable and convenient alternatives. Solar and wind power are already widely used worldwide, but differ greatly from coal-fired power plants as an energy source at their core. The most emphatic difference is that these energy sources depend on natural conditions, such as the amount of sunlight and wind. They are inexhaustible and don’t create toxic emissions.

The biggest solar challange
Let’s zoom in on solar energy. Anyone who ever gets outside, or looks outside, recognizes it: the sun rises in the morning, peaks in the afternoon and quietly disappears behind the horizon again in the evening. For solar panels, the more sunlight there is, the more energy they generate. So as we install more solar panels worldwide, the amount of energy we all generate during the day grows substantially. In the process, the demand for electricity is increasing.

The biggest challenge for solar power is called the Duck Curve. It has been flying around national power grid operators on a regular basis for the past few years. The Duck Curve gets its name – not surprisingly – from its resemblance to the side view of a duck. The orange line represents the amount of energy that coal-fired power plants and other central energy sources have to supply per day. You can see that every year the line drops slightly between noon, and rises in the evening. This change is due to the increased amount of solar panels on roofs of businesses and households. This is because those who generate their own energy during the day – when the sun is shining – are not taking energy from the grid.

A second development in electricity consumption is the duck’s head. This is because every year we use more electricity at night to charge our electric cars, cook on induction and heat the house with an electric heat pump. Conclusion: the valley gets deeper and the peaks get higher.

Why is this a problem?
It is important to power plants and grid operators that the amount of energy needed in a country is stable and predictable. An increasing amount of solar panels kicks this into disarray. When the weather is sunny, the coal-fired power plants produces less. When its cloudy anyway, they quickly re-fire. In regions with many large solar parks, so much energy is generated on sunny days that the power grid cables are not strong enough to transport all the solar energy.

Under certain circumstances, “curtailment” is chosen. This means that manufacturers ensure that the solar panels provide much less energy than they are technically able to. In other cases, a newly completed solar farm is not connected to the power grid at all.

This way we are not going to meet our goals for more renewable energy. Those who hear that the power grid is too weak will think that the solution is simple: reinforce the power grid. But in doing so, we are feeding the duck. Moreover, reinforcing the grid takes years and is extremely expensive.

How do we beat this duck?
Let’s look at the root of the problem. We generate power around the places we don’t use it. Then we need to transport it via long cables. We also generate the least amount of power at the times when we need it the most, and vice-versa. That can be done differently.

One of the biggest advantages of solar panels is that we can install them where the energy is consumed. This means the roofs of households and businesses. Part of the solar energy generated is used directly during the day. The part that remains unused can be stored in batteries. In this way, stored power is always available, even when the sun is not shining.

What’s more, with stored energy from a solar battery, a household, business, school or hospital can operate independently of the energy grid for several hours. This is especially important in countries where blackouts due to weather conditions are common.

In a world where everyone generates and stores their own energy, we can easily distribute it. For example, not all households have a suitable roof for solar panels because they are shaded by tall trees. Those households can now easily use energy generated on the roof of a school or business down the road. So-called “micro-grids” are emerging; mini-versions of the national power grid where energy is generated, used and distributed among them.

Large energy suppliers and polluting coal-fired power plants will become a thing of the past when households and businesses become the power plant themselves. By using a decentralized energy supply on existing roofs, we do not need to reinforce the energy grid. This can be seen, for example, in the construction of a new solar park. In this way we save money and time. Time that we should usefully spend to make our energy supply more sustainable at record speed.

In summary
The rapid rise of solar energy and the increase in our electricity consumption are shaking up the energy world. Grid operators are grappling with a major challenge: the Duck Curve. This is the phenomenon that occurs as solar panels overload the power grid during the day and the peaks in our consumption become higher. We solve this by generating solar energy where it is used and storing it in batteries. This stored energy is used when solar energy is not being generated or shared with households that do not own solar panels themselves. This is how we can make solar energy accessible to everyone.