A study in microgrid ownership effects on investment risk in comparison with underground cabling

This paper studies the effect of joint ownership of microgrids as a means to share the owners' annual cost/profit risks and create incentives for investing in microgrids instead of underground cabling. Underground cabling is acknowledged as a costly and often times unprofitable - but unavoidable - solution for the distribution network operator (DNO) to improve the distribution network resiliency to interruptions in rural areas in Finland. The study demonstrates how the ratio of ownership and mutual agreements would affect the distribution of monetary risk between the DNO and the customers forming the microgrid (i.e. User group), which are the key shareholders. The methodological basis is the standard mean-variance analysis related to volatile assets and the Value-at-Risk concept, which reflects the risk attitude of the shareholders. The methodology presupposes and examines the DNO to be permitted have a double role as the traditional operator of power distribution, and being a small-scale power producer together with the prosumers. The demonstrated case shows how mutual arrangements of ownership shares and fees may be determined such that a joint investment in a microgrid system outperforms the underground cabling solution in terms of annual cost/profit. The study could pave a way to a systematic risk-based means of communicating risk attitude and incentive to form a microgrid in cases where underground cabling seems unfeasible.