Epsilon Archive for Student Projects

Abstract

During the period 2009-2013, investments in the Swedish national grid increase by a factor of ten
compared to previous years. In order to fulfil their mission to manage the national grid in a safe,
efficient and environmentally sound way, Svenska Kraftnät (Swedish National Grid) needs to take all
these perspectives into account while planning new investments. To compare and relate
perspectives of technology, economy and environment the same yard stick must be used. That yard
stick is commonly money. A problem arises however as environmental issues are difficult to price.
The purpose of this master’s degree project was to develop a tool for evaluation of environmental
impact related to investments in the Swedish national grid. It was initiated by and conducted at the
unit for Grid development at Svenska Kraftnät. A life cycle perspective was used and the following
stages were identified: material production, construction, operation and decommissioning. The
environmental impact from these stages was sorted into ten impact categories using the LCIA
method ReCiPe 2008 and then two economical evaluations were performed: one at midpoint level
and one at endpoint level. Also included in the evaluation were the change in power losses or in the
power production mix and the visual impact coming from overhead transmission lines.
Impact categories Type Unit
Part of economic
evaluation
Climate change Midpoint kg CO2 eq Midpoint evaluation
Ozone depletion Midpoint kg CFC-11 eq No
Particle formation Midpoint kg PM10 eq Midpoint evaluation
Acidification Midpoint kg SO2 eq Midpoint evaluation
Eutrophication Midpoint kg P eq Midpoint evaluation
Use of metallic resources Midpoint kg Fe eq No
Use of fossile resources Midpoint kg oil eq No
Damage on human health Endpoint DALY Endpoint evaluation
Damage on ecosystem quality Endpoint disappeared species per year Endpoint evaluation
Resource depletion Endpoint $ Endpoint evaluation
The tool was implemented in Excel and offers the possibility to evaluate the environmental impact
from five different power line technologies (per km), substation line bays (per bay), transformers (per
piece) and reactors (per piece).
The main results show that AC land cable has a significantly higher environmental impact and cost
than the other power line technologies. Material production and construction are the life cycle
stages that contribute the most to the environmental cost. The impact categories that affect the
environmental cost the most are climate change (for midpoint evaluation) and resource depletion
(for endpoint evaluation). When the investment affects the power production mix, e.g. by changing
the transmission capacity to another country, the subsequent environmental impact can be very
influential on the total environmental cost of the investment.