Farm in a skyscraper

The US-university professor Dickson Despommier belives believes in a farm in the shape of a 30 floors skyscrapers in Manhatten. But what problem should be solved in this way?

Energy for the transport of food

Despommier states the transport of food as a major problem. Let's look on the energy usage for thr transport of 1 ton food from Spain to Germany.

Route	Distance	Wh / ton / km	kWh total
Farm to railway	200 km	200	40 kWh
railway station to railway station	2000 km	60	120 kWh
railway to shop	50 km	200	40 kWh
Total	2250 km	75	170 kWh

Energy for electric truck estimated, for the Energie für Elektro LKW geschätzt, für railway transport with real balances.

Energy consume in compare

Work on 1 ha field with the tractor	500 kWh
Irrigation of 1 ha field with seawater desalination	20000 kWh
Electricity usage per inhabitant of Germany	7500 kWh
Diesel and gasoline per inhabitant can be converted to electric power	4500 kWh

Electric tractor estimated with 5 kWh electric power instead of 1 litre Diesel

Diese Zahlen machen deutlich, selbst bei extremen Transportstrecken für Lebensmittel spielt die Energie für den Transport, sofern elektrische Antriebssysteme verwendet werden, nur eine sehr untergeordnete Rolle. Man kann vereinfacht sagen, 1 m² Photovoltaik in Spanien kann jedes Jahr 1 Tonne Lebensmittel nach Deutschland transportieren.