Småkraftverk : en analyse av avvik mellom budsjetterte og faktiske investeringskostnader

Abstract

The potential for small hydropower plants depends mainly on cost- related issues, however geography, soil conditions and the environment are also of great importance. The purpose of this study is to analyze whether the actual cost of investments differs from planned or budgeted costs for 24 small Norwegian power plants that have been in operation from 2007- 2014. The analysis explores the development of cost components in the construction of such power plants. There will be comparisons of cost references from NVE. Surveys of deviation factors are conducted and casual relationships to these factors are examined.

Quantitate and Qualitative research methods are utilized to gather data. In the qualitative part, central data are collected from the power plant owners through phone calls. The quantitative dimension consists of obtaining cost data from a questionnaire hand out, license applications and data from NVE. Statistical surveys are processed by regression analysis and various charts in Excel. The developing costs of hydro plant components have increased significantly during the last 10 years; however it seems that the costs have become more stable over the last 2-3 years. The conducted analysis in this project shows a clear tendency for owners to overestimate annual production and the economy, as recorded in their license applications. Out of 24 power plants, 96 % had an increased development cost in Kr/ kWh, compared to what was intended and stated in the license application. The difference between budget and actual costs are greatest for planning/administration and inlet / dam, and lowest for machine and electrical components. Inlet / dam, and machine /electrical components are dependent upon the annual production. For the power plant station it turns out that the partial costs are approx. 5 % higher than the estimates in NVE`s supervisor for small power plants. Partial costs for power line turns out to be approx. 10 % lower than the estimates. It is observed that many projects have poor feasibility studies, which means that the design takes longer to execute than expected. This problem leads to a lack of detail reviews of construction work on the inlet /dam and pipeline, which causes major challenges, related to incorrect calculations of; ground conditions, extraction of masses and pressure load changes on the pipeline. As a result, this leads to significant added costs for construction work. Owners are also disregarding from the minimum and similar mitigation measures in the application. When these requirements come from NVE, the annual production becomes less compared to the planned application value. At the same time, the uncertainty of work as well as increased labor leads to increased costs. The analysis of differences in mean annual production, total development cost and partial costs are relatively well- founded with few errors. There is considerable uncertainty associated with the contractor's work and the reasons for discrepancies there.