Off The Grid

In a very literal sense, microgrids deliver the power to become energy self-sufficient and exist off the grid. For this reason, microgrids have sparked the imagination of many enthusiast for decades (my uncle included). However, with recent technical and societal developments microgrids are becoming both more feasible and more needed.

As such the sector is in a period of rapid growth. It is reported that the microgrid market will grow with a compound annual growth rate (CAGR) of 27% between 2021 and 2027, reaching a global valuation of $33 billion.

Technical Advances

From a technical point of view, advances in the generation, control, distribution and storage technologies have all helped move this nascent market mainstream.

For example, the cost of solar panels (photovoltaics "PV") and batteries has plummeted in the last 10 years, helping drive adoption and spurring along innovation.

New solar energy technologies such as micro concentrators and advanced materials like perovskites have garnered a lot of attention and excitement recently. The hope is that through new technologies, solar efficiency could break through the maximum theoretical efficiency of silicon-only panels, which sits at 30%, and reach the giddy heights of 47%.

Even though a recent article in the MIT Technology Review questions whether reality will match the hype, the rapid growth of the market is encouraging investment into innovation like we've not seen before.

Solar Power and the Circular Economy

With all the good that PVs can bring, the rapid growth of the market and the relatively short life times (25 years) has brought into focus the challenge of recycling these complicated composite technologies. Typical solar panels are made of glass, plastic, aluminium, silicon, copper, lead, tin, indium and other materials, including toxic metals such as cadmium.

To date, the cost of recycling these complicated structures has simply dwarfed the cost of disposal, meaning many end of life panels head straight to a pit in the ground. That’s a big problem, because at the end of 2016 there was almost a quarter of a million tons of solar panel waste, and the International Renewable Energy Association (IRENA) predicts this will grow to 78 million tons by 2050.

However, innovation is happening here too. In 2017, Veola launched the first of its kind solar recycling plant in France, recycling 96% of the 4,000 tonnes a year that they receive. In the UK, Recycle Solar aim to be able to recover 90% of the glass and up to 95% of the other valuable semiconductor materials.

Energy Storage and Batteries

One of the challenges of renewable energies is that many of them are periodic, sporadic or transient, meaning storage becomes and even bigger issue. 

Batteries, such as those the UK plans to use from Tesla, get a lot of the attention when it comes to energy storage, but the market is innovating in many other ways, too. Energy Vault is taking a leaf from the hydro-power play book, and converting excess renewable energy into potential energy using towers and gravity. 

Batteries innovations are rife. As previously covered, UK company Cheesecake Energy plan to store energy using compressed hot-air, whilst a college in the UK is leveraging both electric and thermal batteries to cover power and heat requirements for their campuses.

Energy sharing

With the ability for any of us to generate energy, there has been a lot of focus on how to trade and manage these distributed, decentralised energy supplies. 

Many solar-equipped households are already benefiting from payment plans that allow them to get compensated for drip-feed excess capacity back into national networks. The same capability is evolving for electric vehicles too - when your car is plugged in, fully charged and not going anywhere for a few hours, why not trickle some of that back to the network and get paid for it? 

Beyond this, Virtual Power Plants are turning communities into mini power stations, and enterprises are finding ways to generate more power than they need from their real estate, too.

This all gets a bit messy, so many companies are trialing Blockchain technologies to help manage the fair trading of energy across heavily distributed generation capabilities.

A recent microgram deployment by PLS Energy Systems in Cyprus Find out more

Powering Communities with Microgrids

Leveraging these trends, companies like Sweden’s PLS Energy Systems, are building and deploying self contained systems to power remote or isolated communities. Their work is already powering schools and medical facilities across Africa, and recently they launched a system on the island of Cyprus.

The company has a track record of delivering microgrid renewable energy systems to Mediterranean islands as well as to rural African communities. Working with strategic partners, such as the East African Power, PLS Energy Systems has deployed solutions of different scales in countries including Rwanda and Ghana. Whilst these microgrids are primarily intended to power schools or medical facilities, there are many other positive ramifications too. 

Speaking with their Chairman, Mr Fredrik Stigebrandt, I learned how one of their micro grids is being used to power a school, but also to charge the community’s mobile phones - something which is having a significant economic and livelihood upside for residents, who previously had to travel significant distances to simply juice up their phones.

Our aim is to provide clean energy where it helps the most, either from a need perspective, like Africa, or from a climate perspective such as in the Mediterranean where almost all electricity is fossil, despite the great conditions for solar.Mr Fredrik Stigebrandt

Doing things differently

Mr Stigebrandt went on to tell me that, unlike many others, they are able to build microgrids that combine both solar and wind generators, and can integrate used batteries, as well as new.

So, Are Microgrids The Future of Energy Systems?

I don’t know if I would be as bold as to say microgrids are the future, but I do think they will form part of it. 

Computing power moved from monolithic main-frames to desktop computers. Then desktops became laptops with enough compute power to become almost entirely self sufficient, running all the applications we needed with no external help.

Then compute moved away from the device, to the Cloud, enabling thinner clients and smartphones. Now the pendulum has swung back the other way again, and we live in a world with distributed computing across billions of devices connected to thousands of cloud compute platforms. 

Energy systems are evolving in a similar way.

Whilst a majority of a typical country’s power mix still comes from big-ticket power plants, there is an accelerating contribution from a greater number of lower capacity devices - such as wind, solar, wave, tidal and ground-heat.

We could see microgrids as the evolution of computing to the laptops and early smartphones of the 2000s - self sufficient and minimally connected. Moving forward, these grids will become more aware of, and more connected with other grids (large and small), creating a network of intelligent grids and distributed power generation and storage - as we saw compute power become less self-reliant and more integrated with both Cloud and other devices, such as IoT systems.