Food growing: electricity instead of land and water

Jordan has approximately 61 cubic meters of renewable freshwater available per capita per year. This is far below the international threshold of 500 cubic meters per person per year, which defines absolute water scarcity. To grow food, you need water. This limits Jordan's food production. It is possible to reduce water usage drastically by using much electricity.

How could the greenhouse in Vienna be improved? Maybe a winter break? How long should the winter break be? Advanced greenhouse: Very low air exchange. The air exchange is controlled by holding the oxygen level below 25%. At the air exchange, humidity recovery is used. CO2 is blown into the greenhouse to achieve the 800 ppm CO2 optimal level for growing tomatoes. The CO2 can be provided by DAC - Direct Air Capture or from cement factories heating the clinker electrically, only providing pure CO2 from the chemical reaction. Water for cooling is cooled down during the coldest hours of the day to improve the COP of the heat pumps. A GEMINI 60 house has 40 m³ water as low-temperature heat storage, which can be used for this optimization. In aeroponic/hydroponic setups, the recirculating solution concentrates salts over time as plants transpire pure water. To prevent toxicity (maintaining EC <2.5–3 dS/m for tomatoes), a fraction must be periodically discharged and replaced with fresh water. For a further reduction of water usage, this water is also recycled as well as economically feasible. Vacuum glass is decreasing in price, so it will soon be a solution to reduce the heating demand at greenhouses in winter. LED usage: Amman has enough light all year to grow tomatoes. In Vienna, the decision is to supplement natural light in winter with LED light for optimal plant growth. The outcome in kWh/kg tomatoes is nearly the same, but using much more electricity in winter would further decrease the 24×365 conversion ratio.

Abstract
	To meet the necessary cost optimization targets, we cannot hold the energy problem separate from all other problems: another major problem is housing.

Introduction
	Many imaginations about our future had been created in the past with completely different parameters. Unchecked conclusions from the past endanger our future with unbearable costs.

My personal experience with a profitability transition
	Birds can fly without knowing all the terms of aerodynamics. I reacted with my design change to an ongoing “profitability transition” without knowing the term at this time.

Energy transition
	The long way from random electricity from sun and wind towards 24×365 electricity. Overseen profitability transitions have to be considered as major accidents.

The GEMINI principle: double usage of land
	No better solar power plant, no better housing possible on the same ground is the ultimate target of the GEMINI principle.

Off-grid fast charging settlements
	It can start small, somewhere in a village, with a single GEMINI house with a big PV carport and 100 kW DC charging.

Energy-intensive industry
	I once developed a scale for off-grid solar possibilities depending on photovoltaic size. But now is to make a big jump upwards on this scale: running, energy-intensive industry.

Agriculture: How many square meters does a human need for his food?
	Mankind started as hunters and gatherers. 12,000 years ago, 500,000 m² to 2,500,000 m² per human. With the agricultural revolution, the land use was reduced by 2 magnitudes.

Conclusion
	All parameters are in a constant state of change. We have to check all the parameters and predict the development for the predictable future.

References
	Roland Mösl: Energy Optimised Settlements – Enabler for Necessary Civilization Targets, Graz 2025