Policy support for renewable energy remains strong despite the Covid‑19 crisis. Although some governments have postponed the implementation of wind and PV auctions since March, the crisis has not provoked the cancellation of any major policy targets or incentives. In fact, some countries have announced ambitious decarbonisation plans and long-term net-zero emissions goals, including the European Union, China and Japan.

Policies have been key to achieve large-scale renewable energy deployment, costs reductions and innovation. The role of policies is changing, however, as wind and solar PV costs have fallen drastically in the past decade. Since 2015, countries have been rapidly transitioning from administratively set FiTs or floating FIPs to competitively set remuneration schemes (auctions, green certificates, etc.) for utility-scale or large-scale distributed PV projects. In the next five years, policy and regulatory frameworks enabling competition will underlie 60% of all renewable capacity expansion globally.

While auctions will remain the preeminent policy scheme, renewable energy expansion outside of government policies is emerging as a key trend. Corporate PPAs, merchant plants and projects receiving multiple revenue streams from tenders, spot markets and bilateral contracts are demonstrating new ways to allocate and diversify risks for wind and PV developers. From 2020 to 2025, the main driver of 9% of renewable capacity expansion is expected to be corporate PPAs and merchant plants, while another 7% is forecast to rely on multiple revenue remuneration schemes. In 2019, only less than 5% of renewable capacity additions were installed outside of main government policy schemes.

Tariffs that are set administratively will continue to be important for renewable energy expansion in China, as the government has phased out wind and PV subsidies. After 2021, new projects will receive fixed remuneration for 20 years at provincial benchmark electricity prices set by the government. Outside of China, FiTs and FIPs account for only 11% of global renewable energy expansion.

New load patterns caused mainly by the Covid‑19 demand shock and extreme weather conditions in some countries/regions have raised electricity security concerns. The curtailment, constraining or “dispatching down” of renewables has been receiving attention as a way for system operators to deal with the inflexibility of power systems during periods of oversupply. However, even though the amount of dispatched-down VRE-based electricity has increased in absolute terms, most systems have been able to evolve to accommodate more VRE.

The amount of dispatched-down energy in a region varies by month and season, depending on a variety of factors associated with system-wide reasons for curtailment (e.g. inertia, ramping limitations, contractual arrangements such as priority dispatch, etc.) and local network limitations or constraints (e.g. grid congestion, faults, etc.) (EirGrid, 2019). Moreover, changes in demand or supply due to climatic and weather conditions, which also affect wind and solar output, also determine how much energy is dispatched-down.

Furthermore, factors such as inadequate market design or system planning to integrate VRE sources; inappropriate locations and volumes for VRE installations; and a lack of flexibility in the electricity system and in infrastructure planning have led to the rise of dispatched-down electricity.

In key markets such as China and Germany, the absolute amount of dispatched-down wind and PV electricity rose 20-fold from 2010 to 2017, with most of the increase coming from China. Over 250 TWh of variable renewable electricity was curtailed – nearly the equivalent of Spain’s annual electricity demand. Had it been possible for this generation to be dispatched or stored for later use, emissions of 180 Mt CO₂1 could have been avoided, which is 3% of total US CO₂-equivalent emissions in 2018 (EPA, 2020a).

China sustained high levels of dispatched-down VRE from 2011 to 2017 (7‑20%), reaching an absolute historical high at almost 50 TWh in 2016. This resulted from rapid deployment of wind capacity in northern provinces, where relatively low provincial demand, limited flexible generation, inadequate dispatch arrangements and interconnection capacity, and interregional trading constraints prevented maximum renewable output dispatch (IEA, 2019). In the same period, Germany, Spain, the United States and Australia also began to significantly dispatch-down wind and solar electricity, reaching almost 20 TWh in 2017.

Since 2017, however, China’s dispatch-down rates have declined significantly, mainly owing to the commissioning of additional interprovincial transmission capacity and improved market operations. The implementation of “investment warning” mechanisms that discourage new installations and project approvals in provinces with high curtailment rates has also helped. As a result of these measures, the share of curtailed VRE dropped from 17% in 2012 to less than 4% in 2019.

Even though dispatched-down VRE electricity overall has increased in absolute terms in the United States, Germany and Italy since 2017, the share of dispatched-down wind and solar PV output has remained stable at 1‑3%, which means that most systems have been able to evolve to accommodate increasing VRE generation as the capacity expands.

Record curtailment levels were reached in California in 2020, with the system operator (CAISO) curtailing over 318 GWh in April (7% of VRE output) – 67% more than in 2019. California had added 1 GW of wind and solar PV capacity from May 2019 to March 2020, raising VRE output, so monthly VRE shares over demand were at a record high of 29% in April 2020, driven by load-dropping of around 8% (mainly as a result of Covid‑19-related measures) at the same time as solar output peaked. Even though California’s maximum share of instantaneous VRE over demand has reached only 80%, the system’s lack of flexibility to accommodate this electricity has resulted in curtailment.

It must be remembered, however, that the optimal curtailment level is not necessarily zero. Dispatching-down can also be an effective way to cut peaks in generation, as it is not efficient for an entire system to have to accommodate exceptional periods of high VRE generation. Furthermore, it is not always logical from an economic perspective to build all the infrastructure that would be required to avoid dispatching-down (e.g. transmission lines, energy storage or more flexible capacity), as the costs may outweigh the benefits up to a certain point.

A transition to more system-friendly integration of variable renewables is needed, for example by complementing policy support schemes with exposure to competitive market outcomes, since there is little incentive for assets with fixed prices and prioritised dispatch to control outputs.

As VRE shares expand, incentivising (or removing barriers to) storage systems could further limit curtailment as well as foster demand-side flexibility. Storage systems incorporate not only large-scale batteries and pumped hydro, but distributed battery storage and technologies that can absorb electrical energy and then return it the same way later. Electricity storage technologies, including PSH and batteries, can provide multiple flexibility services ranging from the ultra-short to the long term, helping to accommodate increasing VRE shares (IEA, 2020). Batteries can contribute to ultra-short-term (sub-seconds) and short-term flexibility (hours to days), providing value by offering services such as fast frequency response and operational reserve.

As levels of absolute “wasted” (i.e. dispatched-down) renewable electricity rise, appropriate market designs; changes to the grid and to market operations; better forecasting; and efficient co‑ordination and operation of interconnectors will cost-effectively reduce curtailment. Modifying existing system assets (e.g. power plants and grids), investing in infrastructure and developing storage technologies and advanced VRE resources that have the capability to provide flexibility services, will also be necessary for reliable VRE integration.

It has been demonstrated that investments, along with important policy changes and co‑ordination, can significantly reduce curtailment. In Texas, for example, wind curtailment declined from 17% in 2009 to 3% in 2019 thanks to the Competitive Renewable Energy Zone (CREZ) policy, which directed transmission investments to high-potential areas where investments were most needed and also improved forecasting and regional co‑ordination for a larger balancing area. In China, transmission infrastructure investments, flexibility retrofitting of existing coal-fired power plants in some provinces, and the softening of administrative allocations to coal power plants in some provinces have reduced curtailment rates significantly.

Various actions on diverse fronts could be taken to eradicate system-wide barriers and permit proper VRE integration. Enabling VRE to compete in balancing markets would encourage the remuneration of real-time balancing costs and provide additional income for renewable generation, while exposing VRE to imbalance penalties would give producers an incentive to smooth their output and provide better forecasts either at the plant or regional level to reduce uncertainty. Furthermore, incentivising demand-side response, storage technologies and power to X to unlock flexibility and respond to shifts in demand would reduce the need to dispatch-down VRE generation, while designing markets to reflect actual system constraints by giving the right pricing signals would allow better allocation of investments. Some of these practices are already in place in markets such as Great Britain, Spain, Denmark and Australia, and among some system operators in the United States.

Unless renewable fuel consumption rises considerably, maritime shipping will have an increasingly negative long-term impact on the climate as international trade expands. A variety of low-carbon fuels are available for the shipping industry, and momentum for their use had increased prior to the Covid‑19 crisis. Currently, however, they all cost more than fossil marine fuels, which is the primary obstacle to increased consumption. The Covid‑19 crisis has further challenged the affordability of higher-cost fuels for marine shipping and uptake through corporate purchases.

Shipping accounts for three-quarters of all freight transport activity,6 with an overall energy demand of 221 million tonnes of oil equivalent (Mtoe) in 2019 (IEA, 2020a) – only slightly less than the final energy consumption of Brazil. Consequently, shipping accounted for 2.7% of all energy sector CO₂ emissions in 2019 and one‑tenth of emissions from transport, creating a greater climate impact than any individual EU member state.

Unless actions are taken to reduce maritime shipping’s GHG emissions, its climate impact will increase considerably over the long term as international trade expands. If the shipping sector maintains its current policies while other parts of the energy system (e.g. the electricity sector, industry and other transport modes) embark on ambitious emissions reductions, its share of global CO₂ emissions could rise to as much as 7% in 2040, putting shipping in the spotlight.

Consequently, the International Maritime Organisation (IMO) has committed to the long-term target of reducing absolute GHG emissions by 50% by 2050 (versus the 2008 level) and CO₂ emissions per transport activity 40% by 2030. A comprehensive package of measures to achieve these targets is not yet in place, but a more detailed IMO strategy is due in 2023. Some industry participants have set more ambitious targets: for instance, Maersk, the world’s largest container ship operator, aims to attain net-zero emissions by 2050.

The key to reducing shipping’s climate impact is to tackle emissions from oceangoing vessels such as container ships and bulk carriers. Although these large vessels make up only one-fifth of the global shipping fleet, international marine bunker fuels account for 80% of all CO₂ emissions from shipping.

Shipping is considered a hard-to-abate sector. Current regulations to address GHG emissions from ships7 are expected to raise average fleet energy efficiency by only 1.5% annually between 2015 and 2025. Even once design, technical and operational improvements have been maximised, the gap to meet the IMO’s emissions reduction target will likely still be considerable. Marine transport therefore needs to switch to very-low-carbon fuels.

The 20- to 35-year lifespan of marine freight vessels is a key consideration in the transition to alternative fuels. A significant proportion of the largest vessels currently in operation still have many years of service left, with two-thirds under 14 years of age (Equasis, 2018). “Drop-in” low-carbon shipping fuels suitable for the current shipping fleet with no or minimal modification to propulsion systems and associated infrastructure are therefore needed.

Long-term projections for international maritime freight indicate that the direct use of low-carbon hydrogen8 as well as ammonia produced from hydrogen and nitrogen from the air could be key future fuels for a low-carbon shipping sector. These are not drop-in fuels, however, so appropriate vessels, storage tanks and bunkering infrastructure are required for their use. Given that ships launched today may still be operational in 2050, suitable vessels need to be introduced by 2030 to maximise the potential of hydrogen and ammonia to help meet the IMO’s emissions goals.

Competitive bunkering costs are essential for commercial marine logistics services. Fuel can make up 50-60% of a shipping company’s operational expenses (Felby, 2018), although it varies according to the type of ship, service and oil prices. All low-carbon marine fuels currently cost more than incumbent fossil shipping fuels.

Given these higher costs, stimulating low-carbon fuel consumption is challenging in the absence of a comprehensive policy framework to reduce emissions from international shipping, as well as incentives for low-carbon fuel use and widespread carbon pricing to cover shipping. Renewable fuels must also compete with an expanded use of LNG, which emits less CO₂ than fuel oil, but not enough to fully meet the IMO’s 2050 goal on its own. The IMO strategy anticipated for 2023 will therefore be critical to facilitate cost reductions and provide a framework for low-carbon fuel deployment despite its higher cost.

IMO regulations that came into force in 2020 to reduce sulphur emissions from marine fuel use9 have prompted a switch from HSFO to more expensive VLSFO10 and distillate oil product fuels such as MGO. VLSFO consumption is therefore set to increase sixfold this year. All the low-carbon fuels in the table above are low in sulphur and comply with the IMO’s sulphur cap regulation.

From January to August 2020, VLSFO was 35-50% more expensive than HSFO at equivalent crude oil prices. Although market circumstances have been altered by the Covid‑19 pandemic and it is the first year of the IMO sulphur cap regulations, the pricing environment is dynamic.

Nevertheless, VLSFO becoming the dominant fuel for international shipping over the next few years should generally reduce the cost premium of sustainable shipping fuels – although most low-carbon alternatives will continue to be significantly more expensive. In addition, approximately 2 500 ships had been fitted with scrubbers by the end of 2019 and will still be able to use HSFO, representing around 6% of the total applicable HSFO fleet.

Increased standardisation (e.g. of fuel quality and bunkering) for all alternative shipping fuels will encourage their use. Unlike aviation, there is no legally binding fuel standard for the marine sector. Consequently, ship owners and operators eager to make their operations more sustainable are still wary about using new fuels and require assurance (e.g. through comprehensive trials) that their use will not have adverse effects.

The port of Rotterdam, one of the top three ports globally by bunker fuel sales, is home to a cluster of biofuel trial activity. Biofuel use is currently supported economically by a national scheme that allows renewable marine and aviation fuels to be used to meet EU RED targets.11 Tickets are awarded per unit of energy and have reached a value of up to EUR 0.60 per litre of biofuel, depending on fuel quality and feedstock. The scheme is currently undergoing revision. Rotterdam also intends to become a hub for low-carbon hydrogen.

Ports are also central in facilitating bunkering for renewable fuels. Just seven ports account for around 60% of global bunker fuel consumption (IRENA, 2020), so establishing supply chains to serve even one key port could extend the availability of alternative fuels to a considerable share of marine freight vessels. Reduced port fees for vessels using sustainable fuels is one means to stimulate demand.

Although providing regular sustainable-fuel supplies may be easier for liner vessels that have fixed schedules and routes, ensuring a suitable scale of production to meet demand remains a key challenge. In energy terms, the annual fuel demand of just one large seagoing container ship can be the same as for more than 100 000 gasoline-fuelled cars.

The global pandemic has created a more challenging environment for marine freight companies to adopt renewable fuels. In the first half of 2020, cargo and container volumes at ports across Asia, North America and Europe dropped by 10‑17%. In response to lower demand, container shipping companies have idled vessels and cancelled services (termed “blank sailings”), which may cause up to a 7% drop in activity (IEA, 2020d).

This difficult economic climate compounds the pressures of underlying debt burdens for container-shipping operators. The combined debt of 14 major companies reached USD 95 billion in 2019 (ITF, 2020), while last year’s profits amounted to only USD 6 billion (Financial Times, 2020). This clearly impairs the ability of companies to transition to higher-cost renewable fuels in considerable volumes.

At the same time, the drastic contraction in fuel demand caused by Covid‑19 has resulted in significantly lower fossil shipping fuel prices. Between December 2019 and early summer 2020, HSFO prices dropped 50%, LSFO 65%, MGO 60% and LNG around 60%.12 This obviously raises the relative cost of sustainable shipping fuels, and may consequently slow the uptake of demonstration initiatives in the absence of formal decarbonisation targets for maritime shipping. Realising the economies of scale in production and market development that are necessary to reduce the cost of sustainable fuels would therefore be delayed.

The crisis could also discourage companies that would normally procure lower-carbon shipping services to demonstrate their corporate social responsibility. For example, companies such as Ikea and BMW have supported biofuel consumption to reduce the climate impact of shipping their products. This kind of corporate offtake is important to enable investment in renewable marine fuel supplies, and can be encouraged by dedicated marine biofuel initiatives such as the GoodShipping Program.

With very few companies untouched by the crisis, the commitment to pay more for greener shipping services may be put to the test. Without a notable drop in the cost of sustainable fuels, their consumption in considerable volumes could translate into higher logistics costs for customers. This raises the prospect of some customers switching allegiance to companies that continue to use fossil fuels and can offer more affordable services.

However, transferring of business could also happen in places where government policies (e.g. carbon pricing) raise the cost of fossil shipping fuels, causing ships to change their bunkering location to areas where such policies are not in force. The inclusion of ships of 5 000 gross tonnage and above within the EU Emissions Trading Scheme (EU ETS) from 2022 was approved by the European Parliament in September 2020 and will be subject to further discussions with member states before introduction (European Parliament, 2020), while the European Green Deal has indicated that a review of tax exemptions for maritime fuels will be undertaken.

Conversely, measures included in some stimulus packages may boost the development of low-carbon shipping fuels. This includes EUR 1 billion of support pledged in Germany’s stimulus package for marine transport, as well as funds to develop hydrogen refuelling infrastructure for multiple transport modes. Meanwhile, Norway’s green transition package outlines support for “green shipping”.