# Dresden 2014 – wissenschaftliches Programm

## Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

# DY: Fachverband Dynamik und Statistische Physik

## DY 19: Energy Meets Economy: Dynamics and Statistics of Future Energy Systems (joint session SOE/DY/ jDPG)

### DY 19.4: Vortrag

### Mittwoch, 2. April 2014, 12:30–12:45, GÖR 226

**Imaginary Interest Rates and Complex Net Present Value Calculus in Energy Economics** — •Gunnar Kaestle — Clausthal University of Technology, 38678 Clausthal-Zellerfeld, DE

A helpful instrument for evaluating the economic feasibility by integrating cash-flows is the Laplace transform [1], as it is an equivalent for net present value calculation. Mathematic rules known from control theory are able to simplify economic assessments. Introducing interest rates from the two-dimensional plane of comlex numbers expands their descriptive power from purely growth or decline to cyclical processes.

Besides discounting cash-flows, discounting energy flows is also a more general but very important assessment of investments in the energy sector. The limiting EROI-factor is gradually degrading in the fossil fuel sector due to the human nature to go for the low hanging fruits first. Severe long term economic implications have to be anticipated, due to the fact that energy is a very powerful production factor.

Therefore, a controlled transition towards non-exhaustive energy resources with a stable EROI has to be started when discretionary spending in learning investments and the deployment of new technology is still possible. The so called net energy cliff shall be avoided by following an exergy efficient transition pathway. Incentive schemes such as the self-adjusting feed-in tariff for German PV systems can be interpreted as supervisory economic control loops.

[1] Robert Grubbström: On the Application of the Laplace Transfrom to Certain Economic Problems; Management Science; Vol. 13; No. 7; 1967; pp. 558-567.