This presentation covers 3 separate solar devices that provide household energy, energy in the form of heat used in the household. Each device can serve multiple functions, but the bulk of the presentation covers water heating.

Biomass gasification combustion technology is well researched and is one of the best-known methods to burn biomass efficiently with very low harmful emissions. The FA-TLUD stove designed and invented by Tom Reed and popularized by Paul Anderson (DR TLUD) is used in a number of commercially sold products. Unfortunately, they are expensive relative to other improved cook stoves and thus have low installed bases.

The open source FabStove Engine design provides a modular framework for separating the stove structure from the gasifier/combustion engine, allowing the gasifier component to be adapted to many cooking applications and styles. By doing this the gasifier engine can be provided as a kit to stove integrators in different markets, and the common parts manufactured in volume at low cost. This will drop the price for consumers.

This approach is different to the way gasifier stoves have been viewed in the past. Ethos attendees will be provided with drawings and videos of the gasifier engine being used for different applications.

Having invested through our Ener-G-Africa joint venture in pellet fuel production and pellet stoves in Malawi, we recognized that fuel supply and cost factors made pellet fuels and stoves only a partial solution to the devastating destruction of the charcoal trade and CQC was open to other alternatives. By contrast, the Jet-Flame burns found or purchased sticks of wood.

In 2020, CQC assessed consumer’s response in urban Malawi to the Jet Flame in our brick and metal rocket stove as a cook stove and as a total household energy supply package.

This talk presents a recently published journal article that addresses the effectiveness of rock beds (free) in open-fire cookstoves. Testing in the lab and field demonstrates that rock beds increase efficiency by a third. Annually, each cookstove improved with a rock bed will save almost one tonne of CO2e and 700 hours of firewood collection. In Africa, with each 1 USD we can train 50 households. Millions of households are now using rock beds but hundreds of millions of households still need training. You do the math. Massive and immediate climate mitigation can be realized with relatively little funding. Journal article: https://www.sciencedirect.com/science/article/pii/S0973082620302775.

Sawdust stoves can shift cooking from nonrenewable firewood to waste fuels like sawdust, rice hulls, rice straw, maize cobs, maize stalks, bagasse, banana peels and cassava peels. These stoves are underutilized and should have greater testing and dissemination.

We present the wood-fuelled Bhundu Tsotso Stove (Bush Twigs Stove) – a unique product concept that meets users’ needs, aspirations and safety and reduces deforestation. Open fires are fuel inefficient leading to wasteful firewood consumption. Across Africa, rural villages are surrounded by denuded forest zones. The design starting point was to use a widely available but underutilised biomass resource – dead branches and twigs. The structure was optimised around the twig dimensions, typically 30 mm. Additionally, user utility, safety and aspirations were considered. The product suite includes 1-, 2- and 4-plate models, all including an oven.

The Bhundu Tsotso remedies many adverse effects of open fireplaces:
* Looks and functions like a stove
* Is fuel-efficient – a few twigs are sufficient to cook a meal
* Has heat plates; no soot
* A chimney to divert smoke
* Enclosed combustion chamber;
* Height-adjustable stand
* Portable
* Removable ashtray
* Durable steel construction
* Effective heat retention and transfer
* Complete fuel combustion

The products will be attractive; practical to rural households dependent on woody biomass. Twig collecting differs from tree felling as a firewood source, thereby enhancing sustainable use of forest resources.

With an Insulated Solar Electric Cooker (ISEC), a 100 W solar panel directly cooks food while providing off-grid electricity access; but it cooks slowly and only during the day. Storing the day’s energy by melting a phase change material allows ISEC to cook more rapidly as well as cook after sunset. By controlling supercooling/crystallization, erythritol (sugar-alcohol with a melting point of 118 C) becomes an ideal thermal storage material for cooking, and for other thermal-storage processes. The efficiency of thermal storage is comparable to that of more expensive systems using battery storage and induction cooktops. For the past 6 months, I’ve cooked primarily with ISEC at home and discovered that the convenience and utility improve as I adapt to ISEC’s unique opportunities and limitations. The next step is to gather experiences from a diverse community of innovators. Grace and Olivia discuss in a separate presentation how A Global Learning Community of researchers, funding agencies, nonprofits, student groups, and local enterprises develops the open source technology and subsidizes local production and dissemination.

During the last two years, the U.S. Department of Energy has invested funds to advance U.S. wood heating technologies, such as biomass-fired space heaters, central hydronic heaters, and warm-air furnaces. To support DOE’s mission, Lawrence Berkeley National Laboratory and Brookhaven National Laboratory have joined forces to develop simplified test methodologies that will accelerate R&D and enable rapid performance testing that simulates real operating conditions. The simplified test methodologies will guide and inform design decisions prior to investing in costly certification, and they will provide guidance for conducting field measurements. During this presentation, we will provide an overview of the project, present our progress to date, and discuss wood heater innovation funding opportunities.