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This paper explores the price setting of demand-side flexibility, modelled as consumers’ voluntary load reduction, in distribution grids. It develops a long-term equilibrium optimization model with a bi-level setting for voluntary demand-side flexibility. In the Upper Level (UL), the Distribution System Operator (DSO) maximizes welfare by deciding the level of network investments and setting the price for demand-side flexibility. The DSO also sets the distribution network tariff in order to recover the network investment and flexibility costs from the Lower Level (LL) consumers. LL’s active residential and commercial consumers react to network tariffs and to the price offered for their flexibility by investing in rooftop solar and batteries and offering a certain volume of demand-side flexibility when requested by the DSO. The passive residential consumers also provide flexibility by decreasing their load, but they do not invest in rooftop solar or batteries. We find that voluntary demand-side flexibility increases welfare and allows significant network investment savings. We also find that the benefits can reach all types of consumers. Besides, it is opportune to apply price differentiation when setting the price for demand-side flexibility, where applicable.

This paper explores the price setting of demand-side flexibility, modelled as consumers’ voluntary load reduction, in distribution grids. It develops a long-term equilibrium optimization model with a bi-level setting for voluntary demand-side flexibility. In the Upper Level (UL), the Distribution System Operator (DSO) maximizes welfare by deciding the level of network investments and setting the price for demand-side flexibility. The DSO also sets the distribution network tariff in order to recover the network investment and flexibility costs from the Lower Level (LL) consumers. LL’s active residential and commercial consumers react to network tariffs and to the price offered for their flexibility by investing in rooftop solar and batteries and offering a certain volume of demand-side flexibility when requested by the DSO. The passive residential consumers also provide flexibility by decreasing their load, but they do not invest in rooftop solar or batteries. We find that voluntary demand-side flexibility increases welfare and allows significant network investment savings. We also find that the benefits can reach all types of consumers. Besides, it is opportune to apply price differentiation when setting the price for demand-side flexibility, where applicable.

This paper explores the price setting of demand-side flexibility, modelled as consumers’ voluntary load reduction, in distribution grids. It develops a long-term equilibrium optimization model with a bi-level setting for voluntary demand-side flexibility. In the Upper Level (UL), the Distribution System Operator (DSO) maximizes welfare by deciding the level of network investments and setting the price for demand-side flexibility. The DSO also sets the distribution network tariff in order to recover the network investment and flexibility costs from the Lower Level (LL) consumers. LL’s active residential and commercial consumers react to network tariffs and to the price offered for their flexibility by investing in rooftop solar and batteries and offering a certain volume of demand-side flexibility when requested by the DSO. The passive residential consumers also provide flexibility by decreasing their load, but they do not invest in rooftop solar or batteries. We find that voluntary demand-side flexibility increases welfare and allows significant network investment savings. We also find that the benefits can reach all types of consumers. Besides, it is opportune to apply price differentiation when setting the price for demand-side flexibility, where applicable.

Demand-side flexibility can be incentivised to reduce the need for investment in distribution grids either implicitly or explicitly. Implicit demand-side flexibility is when prosumers react to price signals triggered by network tariffs. Explicit demand-side flexibility is when the DSO can contract flexibility. In this paper, we focus on one contractual arrangement: mandatory curtailment by the DSO for a fixed level of compensation. We develop a long-term bi-level equilibrium model. The upper level (UL) is a regulated DSO deciding on the network investment and/or curtailing consumers for a fixed level of compensation. The lower level (LL) consists of consumers, which can be prosumers or passive consumers. Prosumers can invest in solar PV and battery systems. They react to the network tariffs and to the compensation provided by the DSO for curtailing them. The regulated DSO anticipates the reaction of the consumers when investing in the network and when setting the level of curtailment. Network tariffs are set to recover the network costs and the payments made to consumers that have been curtailed. We find that the economics of explicit demand-side flexibility in distribution grids are positive, and they are more positive when tariffs are cost-reflective. This implies that we cannot avoid redesigning tariffs by using explicit demand flexibility. We also find that setting an appropriate level of compensation is difficult in the presence of prosumers and passive consumers. A level of compensation that is high enough for passive consumers will be gamed by prosumers.

Demand-side flexibility can be incentivised to reduce the need for investment in distribution grids either implicitly or explicitly. Implicit demand-side flexibility is when prosumers react to price signals triggered by network tariffs. Explicit demand-side flexibility is when the DSO can contract flexibility. In this paper, we focus on one contractual arrangement: mandatory curtailment by the DSO for a fixed level of compensation. We develop a long-term bi-level equilibrium model. The upper level (UL) is a regulated DSO deciding on the network investment and/or curtailing consumers for a fixed level of compensation. The lower level (LL) consists of consumers, which can be prosumers or passive consumers. Prosumers can invest in solar PV and battery systems. They react to the network tariffs and to the compensation provided by the DSO for curtailing them. The regulated DSO anticipates the reaction of the consumers when investing in the network and when setting the level of curtailment. Network tariffs are set to recover the network costs and the payments made to consumers that have been curtailed. We find that the economics of explicit demand-side flexibility in distribution grids are positive, and they are more positive when tariffs are cost-reflective. This implies that we cannot avoid redesigning tariffs by using explicit demand flexibility. We also find that setting an appropriate level of compensation is difficult in the presence of prosumers and passive consumers. A level of compensation that is high enough for passive consumers will be gamed by prosumers.

Demand-side flexibility can be incentivised to reduce the need for investment in distribution grids either implicitly or explicitly. Implicit demand-side flexibility is when prosumers react to price signals triggered by network tariffs. Explicit demand-side flexibility is when the DSO can contract flexibility. In this paper, we focus on one contractual arrangement: mandatory curtailment by the DSO for a fixed level of compensation. We develop a long-term bi-level equilibrium model. The upper level (UL) is a regulated DSO deciding on the network investment and/or curtailing consumers for a fixed level of compensation. The lower level (LL) consists of consumers, which can be prosumers or passive consumers. Prosumers can invest in solar PV and battery systems. They react to the network tariffs and to the compensation provided by the DSO for curtailing them. The regulated DSO anticipates the reaction of the consumers when investing in the network and when setting the level of curtailment. Network tariffs are set to recover the network costs and the payments made to consumers that have been curtailed. We find that the economics of explicit demand-side flexibility in distribution grids are positive, and they are more positive when tariffs are cost-reflective. This implies that we cannot avoid redesigning tariffs by using explicit demand flexibility. We also find that setting an appropriate level of compensation is difficult in the presence of prosumers and passive consumers. A level of compensation that is high enough for passive consumers will be gamed by prosumers.

Restructuring and liberalisation of the electricity industry creates opportunities for investment in energy storage, which could be undertaken by a profit-maximising merchant storage operator. Because such a firm is concerned solely with maximising its own profit, the resulting storage-investment decision may be socially suboptimal (or detrimental). This paper develops a bi-level model of an imperfectly competitive electricity market. The modelling framework assumes electricity-generation and storage-operations decisions at the lower level and storage investment at the upper level. Our analytical results demonstrate that a relatively high (low) amount of market power in the generation sector leads to low (high) storage-capacity investment by the profit-maximising storage operator relative to a welfare maximiser. This can result in net social welfare losses with a profit-maximising storage operator compared to a no-storage case. Moreover, there are guaranteed to be net social welfare losses with a profit-maximising storage operator if the generation sector is sufficiently competitive. Using a charge on generation ramping between off- and on-peak periods, we induce the profit-maximising storage operator to invest in the same level of storage capacity as the welfare-maximising firm. Such a ramping charge can increase social welfare above the levels that are attained with a welfare-maximising storage operator.

Interconnected regional electricity markets are often subject to asymmetric carbon policies with partial coverage for CO2 emissions. While the resulting problem of carbon leakage has been well studied, its mitigation has received relatively less attention. We devise a proactive carbon policy via a bi-level modelling approach by considering the impact of an emission cap that limits the cost of damage from a regional power market. In particular, a welfare-maximising policymaker sets the cap when facing profit-maximising producers and the damage costs from their emissions at two nodes. A partial-coverage policy could degrade maximised social welfare and increase total regional CO2 emissions with potential for carbon leakage due to a higher nodal price difference. A modified carbon policy that considers CO2 emissions from both nodes tightens the cap, which increases maximised social welfare and decreases total CO2 emissions vis-a-vis the partial-coverage policy, albeit at the cost of greater scope for carbon leakage as it causes nodal prices to diverge. As a compromise, an import-coverage policy, implemented by California, that counts only domestic and imported CO2 emissions could alleviate carbon leakage at the cost of lower maximised social welfare with higher total emissions vis-a-vis the modified-coverage policy.

We explore the role of a transmission system operator (TSO) that builds a transmission line to accommodate renewable energy in order to lower emissions as required by government policy. In contrast to central planning, a TSO in a deregulated electricity industry can only indirectly influence outcomes through its choice of the transmission line capacity. Via a bi-level model, we show that this results in less transmission capacity and with limited emissions control in a perfectly competitive industry vis-a-vis a benchmark centrally planned system. A carbon charge on industry that fully accounts for the cost of pollution damage leads to a perfect alignment of incentives and maximised social welfare only under perfect competition. By contrast, a carbon charge may actually lower social welfare under a Cournot oligopoly as the resulting reduction in consumption facilitates the further exercise of market power.

Traditional analysis of distribution grid user’s reaction to tariffs assumes a low price sensitivity and a lack of alternative technologies to grid connection. This is radically changing with two technology breakthroughs: (1) Photovoltaics (PV) enable domestic and commercial consumers to self-produce energy; (2) Batteries allow self-producers to set both their grid energy and capacity parameters. Contributing to the state of the art, the grid cost recovery problem is modelled as a non-cooperative game between consumers. In this game, the availability and costs of new technologies (such as PV and batteries) strategically interact with tariff structures. Four states of the world for user’s access to new technologies are distinguished and three tariff structures are evaluated. The assessed distribution network tariff structures are: energy volumetric charges with net-metering, energy volumetric charges for both injection and withdrawal, and capacity-based charges. Results show that the new distribution world -open by new technology choices for grid users- is highly interactive and threatens grid regulation not understanding it.

Traditional analysis of distribution grid user’s reaction to tariffs assumes a low price sensitivity and a lack of alternative technologies to grid connection. This is radically changing with two technology breakthroughs: (1) Photovoltaics (PV) enable domestic and commercial consumers to self-produce energy; (2) Batteries allow self-producers to set both their grid energy and capacity parameters. Contributing to the state of the art, the grid cost recovery problem is modelled as a non-cooperative game between consumers. In this game, the availability and costs of new technologies (such as PV and batteries) strategically interact with tariff structures. Four states of the world for user’s access to new technologies are distinguished and three tariff structures are evaluated. The assessed distribution network tariff structures are: energy volumetric charges with net-metering, energy volumetric charges for both injection and withdrawal, and capacity-based charges. Results show that the new distribution world -open by new technology choices for grid users- is highly interactive and threatens grid regulation not understanding it.

In order to limit climate change from greenhouse gas emissions, governments have introduced renewable portfolio standards (RPS) to incentivise renewable energy production. While the response of industry to exogenous RPS targets has been addressed in the literature, setting RPS targets from a policymaker's perspective has remained an open question. Using a bi-level model, we prove that the optimal RPS target for a perfectly competitive electricity industry is higher than that for a benchmark centrally planned one. Allowing for market power by the non-renewable energy sector within a deregulated industry lowers the RPS target vis-a-vis perfect competition. Moreover, to our surprise, social welfare under perfect competition with RPS is lower than that when the non-renewable energy sector exercises market power. In effect, by subsidising renewable energy and taxing the non-renewable sector, RPS represents an economic distortion that over-compensates damage from emissions. Thus, perfect competition with RPS results in "too much" renewable energy output, whereas the market power of the non-renewable energy sector mitigates this distortion, albeit at the cost of lower consumer surplus and higher emissions. Hence, ignoring the interaction between RPS requirements and the market structure could lead to sub-optimal RPS targets and substantial welfare losses.