A new outlook on old grids
The current energy crisis begs for innovative, long-lasting energy solutions. Should we turn to DC?
Energy is taken for granted as congested electrical grids become common talk. Sound hard to believe in such a developed world? Consider the number of electric vehicles on the roads, photovoltaic panels on the roofs of buildings, or even the dozens of home appliances like screens & electric heat pumps. Electricity is hardly an infinite source of energy, and with overconsumption, we are quickly seeing the lack of it.
News on grid capacity from around The Netherlands and California
Headlines all over The Netherlands are overwhelmingly saying the same: we are way past our grid capacity. California is also facing grid capacity issues, despite making strides in the renewables sector. Over the coming years, this trend is only bound to follow suite across Europe and USA. The need for more lasting solutions that also consider sustainability and environmental impact is impending now more than ever.
Are DC microgrids a viable solution?
Most of today’s loads consume energy in DC but end up converting AC energy from the grid to DC, like phone or laptop chargers. These repeated conversions lead to up to 20% energy loss, and therefore lower cost effectiveness. Additionally, many distributed energy sources such as photovoltaic panels are inherently DC, necessitating converter systems to convert them back to AC. This is not an acceptable situation. To begin, it is inefficient since these smaller converters are not engineered to be energy efficient, and more crucially, there are several of these converters in a home. To accommodate these transformations, existing systems based on Alternating Current (AC) will require massive restructuring of the electrical grid. Or perhaps, a second grid on Direct Current (DC)?
Electrical professionals are aware of the historical implications of AC versus DC, the historic war of currents between Edison and Tesla/George Westinghouse. It’s also well-known that AC power prevailed mostly due to its ability to transform voltages, which was required for long-distance transmission and the necessity to minimize losses.
For decades, it was assumed that the conflict had ended, and the future of our planet was assured by the installation of AC systems. This is no longer the case as demand grows and available resources reach capacity. The advancement of electronics, photovoltaics, and storage, among others, has resulted in a reformation of DC-based supply and consumption. Additionally, several advancements in DC motors have increased their robustness and efficiency to levels comparable to those of AC motors.
A sustainable energy utopia
The future of electric grids that connect centralised generation sources to loads may continue to be based on AC, but it does not have to be the case for everything. As a starting point, residential buildings and homes can be entirely powered by DC. Fortunately, most homes are powered by a single voltage level. For each home, a single AC-DC converter can be used to convert the incoming AC electricity to DC, following which everything in the home, from the kitchen appliances to electronics devices can operate on DC. Additionally, renewable energy sources such as photovoltaic and battery storage can all remain DC-based, feeding into the home. The primary converter installed in the home can be bidirectional, allowing excess power to be converted back to AC and supplied back into the grid. This physical separation of the two systems enables homeowners to make their own energy decisions, allowing them more autonomy. Finally, by reducing the number of converters in the home, the need for large, inefficient conversion equipment is eliminated. By combining the capabilities of two systems in parallel, a future as envisioned above enables us to construct the ideal symbiotic relationship between both AC and DC systems.
At DC Systems, this concept of AC with DC grids has been in the making for more than ten years, building a deep knowledge in the field, innovative solutions, and practical applications.
When DC Systems joined Schneider Electric in January 2021, Schneider Electric saw an opportunity to combine its AC expertise with emerging DC technology in safe, reliable applications created by the R&D experts based in The Netherlands. Schneider also found DC Systems’ values and vision resounding with its own themes of sustainability and eco-structure.
The company’s research and development focus on a more efficient power distribution system that yields the benefits of working with DC:
- Systems simplified by moving complexity to components.
- Autonomous systems ensuring microgrid matches demand with supply based on priority.
- Up to 25% energy and CO2 savings by harvesting braking energy.
- Protection for people and property.
Besides these notable advantages of utilizing DC power in parallel with AC, renewable energy sources are yet another in the list of devices using DC, such as mobile phones, laptops and so on. Working with our traditional infrastructures is vital, as reconstructing the grid on a global scale is unachievable.