In addition to user interaction, we are also evaluating four business cases via the Linear project. This enables energy suppliers to incorporate renewable forms of energy into their power grids.
As we continue to shift from fossil fuels to renewable energy sources, households will consume less gas and oil and will switch to heat pumps and electric vehicles. As a result, households will probably be able to cut their use of fossil fuels in half, but they will triple, or even quadruple, their consumption of electricity. The peak loads that must be absorbed by power grids and electricity generation will become much heavier as a result, and this will have an impact on the operation and cost of the electricity network.
Energy suppliers and power grid operators are faced with big challenges. So that they may avoid having to make major investments in new equipment, we are studying whether they can minimise these peak loads and their consequences.
1. Portfolio management
By means of Portfolio Management, energy suppliers practise rate control: they pass on the variations in energy prices in the form of the rates they charge. The households get six different rate categories per day, and these prices change daily based on the projected levels of sun, wind, supply and demand. Each day at 4:00 p.m., the rates for the following day are released. In addition to rate control, we are also studying the potential for a system of automated control in which energy suppliers can switch on household devices in order to unburden the grid.
2. Wind balancing
The energy generated from wind power can be substantial, but regional variations in wind energy make it difficult to predict. Yet it is essential to predict wind levels in order to balance the power grid. If wind production differs sharply from what is predicted, the resulting surplus or shortage must be absorbed. We are researching the potential for a system of automated control in which we switch devices on or off in real time. This might enable energy suppliers to avoid penalties imposed on the energy imbalance market.
3. Transformer Ageing
At the local level, transformers that supply neighbourhoods with voltage have difficulty processing the peaks that result from the use of renewable energy. Linear is seeking to minimise these peak loads by tailoring consumption levels to the amount of energy that is generated locally. We are studying the effect of automatically switching on smart devices during periods with very little base consumption.
By isolating the peak loads, we distribute the power over time, which in turn reduces the temperature of the transformer. This enables us to either extend the life span of the transformer or avoid having to upgrade its capacity, both of which save on costs.
4. Line voltage profile
Most household devices operate on 230 volts. If the voltage is too low, some devices will no longer be able to operate. If the voltage is too high, as during a lightning strike for example, these devices can be ruined. Power grid operators ensure that the voltage delivered to consumers always stays within the allowable margins. Traditionally, the voltage is highest at the transformer, and the further away a home is from the transformer, the lower the voltage. This is due to other homes removing voltage from the line as well as the resistance of the line itself.
Because some houses have been generating their own energy for some years now - via solar panels for instance - the voltage can also rise in the middle of a row of homes. This makes it much more difficult for the power grid operator to keep the voltage within the allowable margins. This is why photovoltaic inverters automatically shut off when the voltage is too high.
We are studying ways to use automated control to optimise the voltage level at the points where individual homes connect to the grid. One example of this would be to switch on the devices of consumers in the different homes in a targeted fashion. In this way we could avoid having to run extra lines between the homes and the transformer. This would entail an expensive investment, not to mention the opening up all of the streets and pavements. And the alternative in which households receive no guarantee of a continuous level of voltage, is not an option.