Christa Roth

Job Title: Director
Company: Food and Fuel Consultants
Country: Germany

Christa Roth is a Consultant for Cooking Energy which is vital for human survival. With a focus on Africa, she assists worldwide to develop locally appropriate efficient technologies for cooking or other uses of heat, based on locally available renewable resources, including climate-friendly solid biomass fuels from sustainable sources.
She started integrating PV-based household energy solutions in her work since 2010, first for low-wattage needs like lighting. She is now exploring high-wattage PV-solutions for cooking in off-grid scenarios to see how and where they fit in the mix of household cooking energy to complement or substitute unsustainable solid biomass cooking fuels.
Christa always puts the users and producers at the centre of any technology development, so that users can get what they want and can afford and local producers or installers can create a sustainable business from the promotion of these technologies.

May 07, 2025Off-Grid: Electric Cooking, Cooling and Water Treatment

09:00 am - 10:30 am

Off-Grid: Electric Cooking, Cooling and Water Treatment

Electric cooking with solar energy is on the rise as both solar and battery technologies continue to improve, making it viable for off-grid homes. One of the main hurdles for solar-powered electric cooking has been energy storage. Cooking typically requires a large amount of energy for a short period, while solar generation is intermittent. However, advancements in lithium-ion and solid-state battery technology have made energy storage more efficient, allowing for cooking after sundown or on cloudy days. The efficiency of electric cooking appliances has also improved: In induction stoves, for example, most of the energy goes directly into heating the pot or pan. Appliances like electric pressure cookers and slow cookers are also energy-efficient. They can be ideal for solar-powered cooking setups, as they require a relatively low, steady energy input over a long period of time. With continuous advancements in solar PV and battery storage, solar electric cooking is likely to spread further in regions where grid access is limited or costly, such as parts of Africa, South Asia, and Latin America. In off-grid areas with limited access to electricity, PV systems are also key for powering refrigerators, freezers, refrigerated containers, and cold rooms. They are particularly valuable in rural or remote settings for storing perishable goods, medicines, and vaccines. New technological developments have significantly increased the efficiency of solar refrigeration systems, minimizing or even eliminating the need for battery power at night and during periods of low sunlight.Solar energy can also be used to purify or treat water to make it safe to drink or for agricultural or industrial use. This method leverages the power of sunlight, either directly or indirectly, to remove contaminants, pathogens, and impurities from water. There is a variety of methods for solar water treatment, ranging from using the sun's UV-A rays and heat to complex solar-powered water filtration systems where PV-generated electricity is used to pump water through advanced filtration systems such as ultrafiltration or RO (reverse osmosis). However, solar water treatment systems are still costly and require advanced technology and expertise.This session will provide an overview of current developments and insights into new applications for solar-powered cooking, cooling and water treatment.