Energy savings by voltage management

The main objective of this project is to develop and demonstrate two new energy optimisation units: The

DVC (Digital Voltage Control) for private households enabling a direct 6-20% saving in power consumption,

and the 10/04 VOU (Voltage Optimisation Unit) for stabilising the supply grid.

DVC

PSS Energy is currently able to reduce the power consumption in large buildings by 5 – 35% by reducing

the voltage and standby consumption. Such systems have been sold and installed in countries with high

voltages such as Denmark, Cyprus and Italy on commercial contracts guaranteeing the savings for the

customers. In short, energy suppliers often deliver higher voltages (up to 253 V in Denmark) than

necessary to cover the demand in a building due to capacity issues in the grid, leading to increased

consumption. Voltage reduction in itself saves up to 15% of the consumption, while additional

management of the standby consumption in i.e. offices, outside office hours, has been documented to give

total power savings of 35%.

With this project a DVC will be developed, able to manage voltage and thereby reducing energy

consumption in the more than 1 million Danish single-family houses, offering a significant business case to

PSS Energy. Further, political motivated goals such as less dependency on imported and fossil fuels and

reduced greenhouse gas emissions will be supported in a very efficient manner.

The benefits for the power supplier will be:

1. Avoided or postponed investment in infrastructure

2. Active monitoring and management of consumption (as opposed to “smart metering”, which is usually

constrained to monitoring)

3. Smart Grid readiness enabled in every single-family house in the supply area.

10/04 VOU

The increasing popularity of solar cells and the possibility of delivering excess energy production to the

national grid are creating huge challenges for supply companies. For the excess energy to be sent back to

the grid, the voltage from the solar cells must be higher, compared with the voltage in the supply grid. This

increases the voltage in the supply grid, and high voltage leads to increased power consumption and

shortens the life expectancy of the electric appliances. Further, in some instances, the energy production

from solar cells is higher than the energy production from the traditional power plant. When this happens,

suppliers have no way of controlling the voltage or the frequency, which leads to an unstable power supply

and in worst case scenario black outs. The 10/04 VOU can be part of the Smart Grid, and help stabilising

the fluctuations and subsequently secure the stability of the power supply. It enables the suppliers to

monitor voltage levels in the power grid and it permits them to regulate the voltage and balance the three

phases, thereby optimising the power quality. Finally it provides the ability to control, and in case of an

emergency, turn off parts of the power consumption.