Solar Home Electrolyser Proof of Concept

THE QUESTION

Can a solar home electrolyser generate green hydrogen on a small scale, and expand access to clean energy for cooking in low-income countries?

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LOCATION: Kenya
SECTOR: Energy
TECH: Clean Energy
TIMELINE: September 2022 - April 2023
PIONEER: Rob MacIver
PARTNER: The University of Strathclyde

The Challenge

Unclean, carbon intensive cooking practice disproportionately affects 2.9 billion people in the world, mostly women and girls. Few options exist that don’t involve the collection of carbon or fossil fuel choices such as LPG which is subject to price volatilities. Unclean cooking accounts for over 3 million premature deaths per annum representing about one quarter of all premature deaths caused by pollutants.

Furthermore, as the effects of climate change impose imminent danger to millions of people across the world, there is a drastic need to transition to renewable energy sources that do not emit carbon dioxide into the atmosphere. Green hydrogen, which is produced by the process of electrolysis, is hydrogen that can be used as an energy source and is carbon neutral in its production. An electrolyser is an apparatus that produces hydrogen through a chemical process that splits apart water into hydrogen and oxygen.

Much of the current Green Hydrogen debate has surrounded the question of how to develop a holistic market around large electrolysers which are then connected to a large-scale power grid. Very little of the focus has centered on small technology that could utilise hydrogen as fuel or generate green hydrogen, similar to the way that Solar Home Systems have already achieved with electricity.

The Idea

The goal of the project was to enrich knowledge and understanding on the solar home electrolyser by eventually conducting demonstrations within humanitarian camps, would lead to increased backing for clean pro-poor options on energy.

The following activities were conducted:

• The identification of cooking demand for a Kenyan household.

• Sizing of an example solar home electrolyser system, starting with an estimate of daily hydrogen needs for cooking and sizing of the PV array.

• Determination of the required balance of plant (i.e. the components necessary besides the electrolyser unit) for a solar home electrolyser system.

What we learned

• The viability of a Solar Home System has been proven to be both ergonomic in its basic design and has the potential to work well using of non specialist parts in the Kenyan context – meeting household cooking needs (1.71 kWh/day).  Existing business models such as small loans or Operations & Maintenance linked “Pay as you go” models could be viable.

• Cost reduction is possible. Current estimates of system cost are around £3,9k However, the report highlights key opportunities to cost levelise a typical system, highlighting that costs dramatically reduce (to £2.2k) if storage capability reduces. The report also highlights that small electrolyser efficiency improvements will be a further large cost driver which will likely reduce cost further.

• The system could become smaller in practice. The report indicates that some components may be resized (solar panels, electrolyser) or may even be superfluous (water purifier, compressor) to a wider system.  However these need further investigation. 

• Adapting cooking devices for hydrogen is important. Indications around the energy intensity of hydrogen needs to be a consideration around gas flow rates for the purpose of cooking.

What happened next?

The next phase of the work should aim to prototype and pilot a viable Solar Home Electrolyser fuelled cooking experience within a humanitarian setting. Expectations for such a pilot would include:

1. A viable prototype to show feasibility for this concept to meet cooking demand in a Kenyan household/ domestic settings with space restrictions

2. Cost levelisation of the system should form the basis of the prototype development. Such lessons will inform the baseline for scale.

3. Demonstration of a range of viable price points for 2 to 3 S.H.E’s and demonstration of the potential for carbon credit leverage.

4. A Kenyan humanitarian camp site identified and agreement to demonstrate in collaboration with UN partners.

5. A range of human experiences / opinions synthesized showing a comparison of demonstration experiences alongside other stacked household cooking options. This leads to the baseline hypothesis for a randomised controlled trial (RCT to be considered within wider FCDO programming).