Beyond Fire, a recently published report by the World Future Council and Hivos (2016) argues that “focusing on improved cook stoves is neither a truly long-term nor a truly sustainable solution to the challenge of cooking.” Their analysis echoes much of our work, indeed they quote from and suggest very similar solutions.
Figure: Comparison of Beyond Fire’s economic modelling results with selected results from Leach & Oduro (2015). The figure below is taken from Beyond Fire, with Leach & Oduro’s (2015) “High Cook” values converted to the same units and superimposed. PV-eCook bars are a combination of Leach & Oduro’s 5% and 20% discount rate modelling. Exchange rate of 1.12USD/EUR, Beyond Fire assume 5 ppl/HH, Leach & Oduro assume 4 ppl/HH.
They point to massive population growth across the Global South, particularly in Sub-Saharan Africa where population is predicted to triple by 2060. This is predicted to far outpace any attempts to produce biomass fuels more sustainably. Whilst LPG may offer an intermediary solution for many, ultimately, it is a fossil fuel. Aside from the implications for climate change, LPG prices will increase exponentially as reserves begin to dwindle,, which will put it economically out of reach for resource poor households..
They present an economic, social and technical comparison of four potential pathways to sustainable cooking:
- SHS (Solar Home Systems), i.e. what we have been calling PV-eCook
- Renewably powered mini-grids, i.e. one variant of what we have been calling B-eCook
- P2G (Power to Gas) – using renewable electricity to electrolyse water, then blending hydrogen with CO2 to produce methane
They find that biogas is the most economically competitive on a levelised cost basis and is already on par with traditional fuels (it also produces a fertiliser as a byproduct which they don’t take into account in their price comparison). We have an eye on the future of biogas, and indeed team members have used it sustainably for many years in certain situations. However, the report argues that the high upfront cost and the ongoing need for both suitable organic feedstock and water present significant barriers. They do say that it is most suitable for rural areas if a suitable financing package can be offered. P2G is a very attractive option, as it can slot straight into the existing LPG supply chain and therefore there are no significant behavioural challenges. What is more, the economics are already competitive and further cost reductions are expected. They note that the distribution of cylinders presents a major challenge, meaning that it is likely to fit best in urban areas.
Their modelling conclusions agree with Leach and Oduro’s, in that at current market prices, eCook is currently slightly too expensive for practical application. However, they also acknowledge that by embedding electrical infrastructure in HHs, it offers the broadest “co-benefits”. As a result, they conclude that: “focusing solely on the P2G pathway for cooking without also improving access to electricity would fail to promote complete and balanced energy access, as intended by many leading initiatives such as the SE4ALL initiative and the United Nations’ Sustainable Development Goals (SDGs). The question then becomes whether it would be more cost-effective to provide electricity in smaller-scale systems (either SHS or mini- grids) that are equipped to meet basic electricity needs, and meeting cooking needs with alternative, non-electric pathways such as P2G, LPG, pellets, or biogas systems. This uncertainty underscores the need for far greater investment in this area, including targeted pilot projects designed to evaluate these various factors.”
Whilst their economic modelling draws heavily on Leach & Oduro’s (2015) work on eCook, there are some important differences. Leach & Oduro built a component model, pricing out each component today (which was 2015) and reviewing price trends to predict the costs in 2020. In contrast, Beyond Fire offers a simplified analysis, taking the LCoEs (Levelised Cost of Energy) for SHS and mini-grids from the literature and simply multiplying this by the number of units needed to cook. They use a figure of 1GJ (278kWh) per person per year in the pot for their analysis, however as they point out, the exact number is not actually that relevant, as they are focussing on monthly cooking costs as opposed to the initial capital and therefore simply need a baseline to compare between the four technological pathways. In fact, this 1GJ (278kWh) figure is closest to Leach & Oduro’s “High Cook” scenario (270kWh) that they defined to model the upper limit of the broad range of culturally embedded culinary practices around the world, and which we have now shown can be mitigated by simple behavioural changes in cooking.
Figure: Beyond Fire’s key modelling parameters (Jacobs et al., 2016).
Strangely, the World Future Council did not look at future costs in Beyond Fire, they merely evaluated comparative costs for the four pathways today. As a result, they come to the same preliminary conclusion as Leach & Oduro, in that the price tipping point for eCook has not yet been reached, however Leach & Oduro did take it to the next stage and their cost forecasting predicts that by 2020 it will be (see the modified figure). Fortunately, they do acknowledge that component costs are likely to continue to fall and as a result, “the SHS pathway is likely to become an increasingly cost-effective solution for sustainable renewable energy cooking in rural peri-urban areas in the future.”
Beyond Fire highlights the following challenges for eCook:
They say – Limited potential for major improvements in appliance efficiency
We say- we have already seen that with small inputs behavioural changes can be nudged and that significant energy savings can be made.
Unlike LEDs, which revolutionised the solar lighting industry, there is relatively little scope for increasing electric cooking appliance efficiency without introducing significant behavioural change challenges. As a result, in line with Leach and Oduro’s modelling, they note that the batteries and PV modules are where the major enabling cost reductions and performance increases are likely to occur.
They say – High upfront capital cost (implied barrier)
We say- that this is true for all renewable energy, including biogas, but new business models of ‘Pay as you go’ service models increasingly overcome this challenge.
The success of eCook will no doubt depend on the availability of innovative financing mechanisms that will enable people to pay back these costs in a similar way to how they currently pay for traditional fuels.
They say – Reversion is a risk
We say – we agree that fuel stacking will likely continue, and that rainy days and extended family gatherings will mean that people break out the old charcoal stove. However, that shouldn’t deter us from making the everyday cook to be with modern energy.
Beyond Fire predicts fuel stacking to be high for eCook, as “electric pathways have been shown, in practice, to be less effective at actually displacing firewood and charcoal use than biogas and other similar systems (World Bank 2014). Field research has shown that introducing electric cooking only reduces the consumption of firewood and/or charcoal between 10% and 40%. In contrast, the displacement rate for households equipped with biogas systems has been shown to be significantly higher, ranging between 66% to as high as 80%.”
Firstly, reviewing the World Bank’s (2014) original report reveals that this figure is in fact misquoted, as electricity is not even mentioned in their fuel stacking estimates, however solar cookers are: “e.g., 30–70% biomass fuel savings for users transitioning to LPG, 66–80% for biogas, and 10–40% for solar.” Even if 10-40% were the figure from previous research on electric cookers, this would most likely only be true for grid connected systems, where users have to pay high costs (or at least perceived high costs) for each meal. In contrast, biogas costs the user nothing extra per meal, as the fuel is already in the tank whether you use it or not. The same would apply with PV-eCook and partially with B-eCook, depending on the financing models employed. Once the cost of the components comes down to the tipping point whereby there is no longer a cost motivation for HHs to switch back to traditional fuels, fuel stacking behaviour is likely to be driven primarily by cultural preferences and the power and energy limitations of the particular eCook device (battery capacity, PV array size, maximum power output of the hob). As a result, with a properly designed system, there is no reason why eCook could not achieve the same figures as biogas, which also suffers from a limited energy supply due to the finite amount of gas generated each day.
They say – Shortened battery life
We say – work on batteries for electric cars and energy storage is so ‘in’ at the moment that short battery life will soon be a thing of the past. (and not forgetting super caapacitors to mitigate peak loading)
This was the question addressed by Slade (2016), however the results were inconclusive, pointing to the need for in depth testing on Li-ion and other relevant emerging battery technologies at elevated temperature and rapid discharge. This will indeed affect the economics and therefore overall viability of the proposition, however with the electric vehicle industry pushing battery technology forward at an incredible speed, it seems unlikely to be an unsurpassable technical challenge and will in fact, simple reduce the market size rather than completely invalidate the concept as even current battery technology could do the job, just at a higher cost.
They say – Inability to internalise externalities (is a challenge)
We say – the added societal advantages are likely to drive eCook into the future.
This point refers to the health and environmental benefits of eCook over LPG, firewood and charcoal. They say that at current market prices, eCook is only cost competitive if you internalise these additional societal benefits. However, as the price tipping point is approached, these will become strong drivers for change at a societal level, when policy makers have to choose amongst similarly priced options.
They say – Simultaneous peak loads on mini-grids (are a problem)
We say – peak loads are mitigated by household level storage.
In Beyond Fire, they only consider cooking directly off of a centralised battery bank, which of course will create big problems when everyone turns on their stove at the same time to prepare dinner. However, it doesn’t mention HH battery storage as a way to mitigate this, i.e. what we have been calling B-eCook. At both the national grid and mini-grid levels, this offers a potential solution for this simultaneous peak load issue, with the additional benefit that the HH would still have power (for cooking and other lower power applications) even during blackouts. What is more, as cabling is often a significant cost for mini-grids, it would be worth extending Beyond Fire’s modelling to compare the economic trade offs of connecting HHs with thinner cables (sized for trickle charging only) and a HH battery vs thicker cables (sized for peak cooking loads).
We like their report because it creates debate, but as you can see, we dont necessarily agree with their conclusions!
- Jacobs, D. et al., 2016. Beyond Fire : How to Achieve Sustainable Cooking, Available at: https://www.worldfuturecouncil.org/file/2016/10/WFC_BeyondFire_web-version.pdf [Accessed June 8, 2017].
- Leach, M. & Oduro, R., 2015. Preliminary design and analysis of a proposed solar and battery electric cooking concept : costs and pricing, Centre for Environmental Strategy, University of Surrey (comissioned by DfID)
- World Bank, 2014. Clean and improved cooking in sub-Saharan Africa: A landscape report, Washington, D.C. Available at: http://documents.worldbank.org/curated/en/879201468188354386/pdf/98667-WP-P146621-PUBLIC-Box393179B.pdf [Accessed June 1, 2017].