Small studies might overestimate the potential
This review shows that the average energy reductions are higher in studies with fewer participants, hence an inverse correlation was found by comparing the reviewed case results.
Whether this is true only for these smart metering cases, or in general, cannot be known, but this shows that limited case study results must be handled carefully in prediction of a solution’s wider potential.
For the reviewed smart metering cases it can be noted that many studies are done on a voluntary basis, and it is likely that mainly enthusiastic early adopters participate in such pilot studies. There is also a possibility that people are more willing to change behavior knowing that it is a trial for a certain period. When the energy data is no longer a novelty, they might fall back into their old habits.
Common methodological shortcomings
Studies estimating the future potential benefits of specific ICT solutions, often extrapolate results from a case study to a larger region, country, or the entire world. As the smart metering example shows, there is then a risk that potential reductions are overestimated by assuming that the same reduction is possible for all users and everywhere.
Three common causes of flawed extrapolations:
- Other influencing factors are overlooked.
Something else might have happened at the same time, like installation of a heat pump. Also, the average outdoor temperature also needs to be accounted for comparing different periods.
- ICT´s carbon footprint is not included.
The impact from the ICT solution should be considered, including all life cycle stages like production and use.
- Potential uptake is not considered.
The representativeness of the case study needs to be assessed. The potential uptake of the ICT solution should be considered before any extrapolation, as similar solutions might already exist in other parts of the world.
Sufficient reductions needed to offset solution footprint
Three different scenarios of reducing the average electricity consumption in households due to ICT solutions for both smart metering and thermostat monitoring/control systems were created, based on the reviewed case studies. The intention is to show ICT’s impact together with the assessed reductions while framing the large variations in the carbon intensity of the grid between countries.
A low reduction scenario of 2%, yields an enabling effect that can be conservatively claimed today. For the medium reduction scenario of 4% a near real-time feedback and active households is required.
A high reduction scenario of 8% is seen as a best-case, assuming that all households are active and can achieve what the best performing households have shown possible already today. Additional solutions for balancing and optimization of load based on the smart meter data are also included in the high reduction scenario.
In the three scenarios, the carbon footprint of the ICT solutions is in most cases outnumbered by the potential reductions of CO2-equivalents (CO2-eq), but it can be significant and should always be included in this kind of studies to derive the actual effect.
Current home energy management systems with monitoring and control solutions, included in the medium and high reduction scenarios, show that the impact from ICT´s own footprint should not be neglected. A reduction of about 4% is needed to be clearly beneficial compared to ICT’s own impact.