By now, we all know that global warming is slowly boiling our planet. We also understand that it is caused by a long list of human activities, with our insatiable hunger for energy right at the top. Yet our current efforts to counter it are lagging behind the rising temperatures. Renewable energy sources are only part of the solution. The other part is greater energy efficiency. Our houses, shops and factories waste gigantic amounts of energy, often in the form of excess heat. How do we slash this waste? The answer is fairly simple: with a smart thermal water grid.

When we think about future energy systems, we usually think only of electricity. We imagine smart power grids that integrate and deliver electricity for different purposes, like powering household appliances and commercial buildings, or charging electric vehicles. What power grids cannot do is dramatically reduce the amount of energy wasted at the source. Here is where the power grid’s twin – the smart thermal water grid – comes into play.

The idea is to take district heating to the next level. Think about it: today, supermarkets produce copious amounts of excess heat to keep their freezers on 24/7. Factories and other industrial sites also need permanent heating or cooling systems. The excess heat is simply released into the air or the sea. We are heating our birds and fish, when a temperature change is the last thing they want. We could retain that excess heat and redirect it to where it is needed. Buildings, supermarkets and factories could exchange surplus heat directly with each other or distribute it to residential buildings. All we need is the right distribution system. Most countries already have all the energy they need for heating and cooling – they just can’t redistribute it.

Supermarkets and factories could exchange surplus heat directly
Supermarkets and factories could exchange surplus heat directly
Image: Crystal Kwok/Unsplash

A smart thermal water grid would do just that, and much more. By expanding and integrating existing district heating infrastructure, we would be able to use the excess heat coming from any wasteful source – from power plants, chemical plants, the refrigeration systems of commercial and industrial sites and so on – at scale. And it doesn’t stop there, because studies have shown that, once this water distribution system is in place, it becomes cheap and effective to add renewable energy sources to it. Osmotic, solar and geothermal energy can be attached, giant heat pumps can recycle the energy from floods, and biofuels and incineration plants can feed in as well.

The road to energy efficiency is in theory a sustainability sweepstake. More efficiency means that less fuel is required to generate a given amount of energy, which in turn means lower costs for the provider and cheaper prices for the customers. At the same time, the grid creates new jobs for the design, construction and management of new energy infrastructure. Last but not least, a lower consumption would pave the way to a greater energy independence – and therefore energy security. Who needs Russian gas, if we could get all the heat we need from our own surplus? Who needs Middle Eastern oil, when we can integrate limitless renewable sources in our smart grids?

At this point, someone might still be wondering why we need a smart grid, and what I mean by “smart” grid in the first place. The problem with most renewable sources is that they fluctuate. The sun doesn't always shine; the wind doesn't always blow. This is why, if we want to rely on renewables, we need intelligent systems that integrate and coordinate different sources of energy at scale, so that when one is scarce or unavailable, the others can automatically compensate.

In Europe, some companies are already developing parts of this vision on a large scale, and a unique project of smart energy system is currently taking off in Copenhagen. It is not by chance that Europe is taking the lead on energy efficiency, since today the heat wasted in the continent is more than that required to heat all its buildings. A pan-European smart thermal water grid would have a huge impact on the environment and on the economy of the world’s biggest marketplace.

Through a smart water grid, we could avoid heating the birds
Through a smart water grid, we could avoid heating the birds
Image: Bill Gierke/Unsplash

To adopt clean and efficient energy systems worldwide, we need to support their development and implementation on a political level, through top-down decisions. District heating markets often lack regulations to ensure transparency and protect customers from unfair pricing (London is a case in point). In addition, despite all the talk about climate change and green energy, our governments are still supporting the consumption of fossil fuels. In 2015, the total subsidies for fossil fuels worldwide reached an unbelievable $5.3tn – $10m every minute! The scope of research and development in renewables that could be achieved with such funding is mind-blowing.

To save this planet, political leaders must take immediate action to ensure we reuse and generate the energy we all need in a sustainable way. For all the talk about smart grids and electrification, water is the faster, cheaper way. When it comes to energy, the smart thermal water grid is a the most efficient and overlooked big idea we have.

This is part of a series of blogs on how to Renew Europe.