Sensors to measure electricity reliability now deployed in homes and businesses in Accra, Ghana

The first phase of the GridWatch project, led by the University of California, Berkeley, is now complete. It involved the design, deployment, and operation of sensors to measure power outages, voltage fluctuations, and frequency instabilities in Accra, Ghana.

Investments in the electricity sector in the developing world have tended to focus on increasing access to electricity. However, for the many households and businesses that are already connected to the grid, the primary issue is poor electricity reliability, rather than lack of access.

Neglecting reliability is often associated with a reduction in the demand, use, and social benefit of electricity. Anecdotally, frequent outages constrain economic wellbeing by reducing the benefits from welfare-improving appliances like fans and refrigerators or income-generating assets like sewing machines.

Studies on the macroeconomic impacts of outages suggest that the costs may be large – in the range of 2-3 per cent reduction in long-run GDP per capita. Poor reliability also impacts hospitals, factories, telecom systems, and government buildings – all of which are important to economic development.

As more and more people living in the developing world gain access to electricity, the focus of policy makers is shifting towards understanding the quality of that access, and investments are increasingly aimed at improving the reliability of electricity distributed on the existing grid.

However, improvements in electricity reliability can be harder to measure – and to achieve – than improvements in access. To improve reliability, a utility needs fine-grained information about grid performance in addition to well-developed tools to address problems. Many electrical utilities are already under-resourced for the complex and expensive task of planning, extending, and operating their current systems, and cannot easily launch programmes to collect the data needed for increasing reliability.

Utility operators have very low-quality information on outages. Many utilities won’t know there’s an outage on their distribution system unless someone calls to report it (or, increasingly, reports it via social media). But customers may not call, may not experience all outages (e.g. if they are sleeping), and few would call once power is restored. And even when an outage is reported, the utility may not know when it started or how long it lasted, how many customers are affected, or what fix may be needed.

Over the past year, a team of engineers and economists from the University of California, Berkeley, has developed, deployed, and operated a suite of low-cost, remote sensing devices, collectively called GridWatch. Unlike existing technologies, GridWatch automatically measures and centrally collects data on grid reliability and power outages, publicly and independently of utility reports.

The team developed two different sensors that detect the presence and absence of grid power: an app called DumsorWatch that is installed on a participant’s mobile phone, and a fixed-point sensor called PowerWatch that is plugged in at a home or business (with a battery to allow for continuous reporting throughout a power outage).

The DumsorWatch app automatically senses power outages and power restorations by using a combination of on-phone sensors to determine probabilistically whether the electricity nearby is working, and cloud services. Meanwhile, PowerWatch integrates power reliability sensors with a GSM radio, allowing for measurements to be sent in near real-time to a cloud service. It senses power outages and power restorations timestamped to the millisecond, GPS-based location, voltage, and grid frequency.

Using consumer plugs and consumer phones, as opposed to directly measuring the electric grid, negated the need to depend on direct access to utility infrastructure such as transformers or lines, and the team didn’t need prior approval or cooperation from the utility to deploy the sensors.

The deployment of each PowerWatch device was accompanied by a socioeconomic survey of approximately 60 minutes in length, and a shorter survey was administered to respondents who did not receive PowerWatch but did download DumsorWatch.

During the pilot stage and the EEG-funded Phase 1, over 400 PowerWatch sensors have been installed, 3,400 individuals have downloaded the DumsorWatch app, and nearly 3,000 participants have been surveyed. The team attempted a 50 per cent split between households and firms.

The team selected sites that are being improved by the Ghana Power Compact, which is a USD535 million investment designed to improve the grid generation, transmission, and distribution systems in Ghana to be implemented by the newly created Millennium Development Authority (MiDA), and quasi-randomly selected control sites comparable in observable characteristics.

By comparing households and businesses whose socioeconomic characteristics are identical in expectation, and that differ only in terms of the quality and reliability of power they receive, the team will be able to learn more about the socioeconomic benefits of improved reliability, and estimate the causal effect on outcomes such as wellbeing, productivity, and health for the residents of Accra.

GridWatch’s improved information will also help utilities to quickly and accurately assess the extent of an outage, so they can dispatch repair crews where they’re most needed to better prioritise limited resources. With a little more analysis, GridWatch data may also help the utility to carry out better preventative maintenance. For example, by comparing the sensor data with the utility’s electrical infrastructure, GridWatch might be able to identify outage patterns that can pinpoint specific pieces of equipment that are more likely to fail.

The first phase of the project took place in Ghana, because unlike many countries in West Africa, it has already begun to explore options for improving reliability. In the second phase, the team will scale deployment across the city of Accra and beyond.

GridWatch has the potential to help governments and utilities make far more informed investment decisions. The research team will work with regional policy makers to understand how information provided by a system like GridWatch could best be used to improve energy decisions, and will use the data collected to measure the economic costs of unreliable electricity systems.

The team’s paper, Hardware, Apps, and Surveys at Scale: Insights from Measuring Grid Reliability in Accra, Ghana, can be found here.