Why Solar Alone Will Not Get Jamaica to 50% Renewable Energy

JAMAICA’S ENERGY FUTURE: FROM AMBITION TO ACTION: Article 3 of 5

Emanuel DaRosa

Chief Executive Officer at SunTerra Energy Ltd

June 30, 2026

In the first two articles in this series, I outlined two central realities. First, Jamaica is not currently on track to achieve its target of 50% renewable electricity by 2030.

Second, Uruguay’s experience demonstrates that a national energy transformation is possible when clear policy, long-term planning, private investment, and disciplined execution are aligned around a common objective.

The next question is technical, but it is also fundamental: What type of renewable energy system does Jamaica need?

Given solar energy is one of, if not, Jamaica’s greatest natural resources, it must play a major role in Jamaica’s future. We have an excellent solar resource, declining technology costs, available land, experienced developers, and growing access to climate and infrastructure finance.

However, adding more solar generation by itself will not create the energy system Jamaica needs.

To understand why, we must distinguish between three very different concepts:

• Installed capacity

• Annual energy production

• Firm capacity available when the system needs it

These terms are often used interchangeably in public discussion. They should not be.

Capacity Is Not Energy

A solar plant may have an installed capacity of 50 megawatts, but it does not produce 50 megawatts continuously. Its output varies throughout the day and with weather conditions. It produces no energy at night unless it is paired with storage.

The same principle applies to wind generation. A 50-megawatt wind farm can produce close to its full output in favourable conditions, very little when wind speeds fall, or nothing during certain periods. Installed capacity tells us what a plant can produce under specified conditions.

Annual energy tells us what it actually contributes over an entire year. Firm capacity tells the system operator what can reliably be called upon when demand is high or another generator becomes unavailable. All three matter.

Jamaica’s challenge is that our national target is expressed as a share of annual renewable energy, while the electricity system must be operated securely every second of every day.

What Jamaica’s Existing Fleet Tells Us

Historical operating data provide a useful picture of Jamaica’s current generation system. The major renewable plants and JPS hydroelectric stations represent approximately 187 megawatts of installed capacity and produce about 540,000 megawatt-hours of electricity annually. That equates to approximately 12.6% of Jamaica’s annual electricity generation.

The individual plants perform differently:

• JPS hydroelectric plants have historically achieved a combined capacity factor of approximately 55%.

• Paradise Park, also known as Eight Rivers Solar, has operated at approximately 26%.

• Content Solar has operated at approximately 25%.

• Wigton Wind has operated at approximately 27%.

• BMR Wind has performed strongly at approximately 39%.

• Munro Wind has contributed very little energy and has historically operated at approximately 3%.

These results demonstrate two things. First, Jamaica’s existing renewable plants are valuable national assets. Second, their output is variable and cannot be treated in the same way as firm thermal generation.

Solar and wind can reduce fuel consumption and emissions, but without storage or another source of firming capacity, they cannot independently guarantee supply during evening peak demand, periods of cloud cover, low wind conditions, or unexpected system events.

The Instantaneous Penetration Challenge

Jamaica’s highest system demand is just under 700 megawatts, while a more typical operating load is approximately 550 megawatts. Existing solar and wind capacity can therefore represent a significant proportion of the system at particular moments. Under favourable conditions, solar and wind may contribute approximately 20–25% of instantaneous system demand.

In theory, total installed intermittent capacity could represent close to 25% of a 700-megawatt peak and more than 30% of a 550-megawatt operating load.

In practice, the plants do not all produce at full output simultaneously. Nevertheless, the system can still experience rapid changes in renewable production that are large relative to the total size of Jamaica’s grid.

This distinction is important. Solar and wind may provide only a modest share of annual energy while still having a substantial effect on real-time system operations.

A large continental grid can absorb fluctuations across wide geographic areas and thousands of generators. Jamaica operates a comparatively small, isolated island grid. There are no neighbouring electricity systems available to absorb excess production or provide immediate support when renewable output declines. The entire balancing responsibility remains within Jamaica.

The Operational Consequences of Intermittency

Electricity supply and demand must remain balanced continuously. When cloud cover causes solar output to fall rapidly, another generator must also rapidly increase production to keep the system balanced on a second by second basis.

When solar generation declines at sunset while customer demand remains high, thermal plants must ramp upward quickly. When wind output changes unexpectedly, the system operator must respond within seconds or minutes.

These fluctuations affect:

• Frequency stability

• Voltage performance

• Spinning-reserve requirements

• Thermal-plant cycling

• Fuel efficiency

• Maintenance costs

• System reliability

During my tenure as CEO of JPS, the effect of intermittent generation on system operations was not theoretical.

The variability associated with the existing renewable fleet contributed to the need for approximately 27 megawatts of battery and flywheel capacity to provide rapid-response grid support. These investments helped manage frequency and load fluctuations that conventional thermal plants could not always address quickly enough.

JPS also expressed concern that continuing to add intermittent generation without sufficient storage, reserve, or flexible generation would increase the difficulty of operating the national grid reliably.

This does not mean Jamaica should stop developing renewable energy. It means we must develop it differently.

The Duck Curve

As solar capacity grows, daytime electricity production increases significantly. This can reduce the amount of electricity required from thermal plants during daylight hours. However, customer demand often remains high after sunset.

When solar output falls rapidly in the late afternoon and early evening, conventional generators must replace that lost production within a relatively short period. This creates the operating pattern commonly known as the “duck curve.” The deeper the daytime solar contribution becomes, the steeper the evening ramp can become.

Thermal plants may be required to operate at low output during the day, consuming fuel inefficiently, and then ramp sharply in the evening. Rather than replacing the thermal fleet, solar-only development can create a two-fleet system:

• Solar generation during the day

• Fossil generation during the evening and night

In that configuration, consumers will still be required to pay for the capital and fixed operating costs of both fleets. The country gains renewable energy, but it does not necessarily eliminate the need for conventional capacity.

The Next 100 Megawatts

This issue will become more important as Jamaica’s next major renewable plants enter operation. The projects currently expected for 2027 include approximately:

• 50 megawatts from SunTerra Energy Jamaica

• 49.83 megawatts from Wigton

Together, these projects will add almost 100 megawatts of new renewable capacity. Their expected annual production is approximately:

• 130,000 megawatt-hours from SunTerra

• 115,000 megawatt-hours from Wigton

This additional renewable energy is important and welcome. However, the operating effect of nearly 100 megawatts of additional daytime-variable generation on a system with a normal load of approximately 550 megawatts must be carefully planned.

The combined existing and new intermittent fleet could approach 270 megawatts of capacity. That is almost half of Jamaica’s typical daytime operating load. Actual simultaneous output will generally be lower, but the potential scale of the ramping and balancing requirement is clear.

Jamaica must therefore plan not only for how much renewable generation is added, but also for how and when that energy is delivered to the grid.

Storage Changes the Equation

Battery energy storage allows renewable electricity to be shifted from the time it is generated to the time it is needed. Instead of forcing the grid to accept all solar production during daylight hours, energy can be stored and released during the evening peak or overnight.

Storage can also respond much faster than most conventional plants, helping to regulate frequency and manage sudden changes in supply and demand. When solar generation is properly paired with storage, it can:

• Smooth fluctuations

• Reduce the evening ramp

• Supply energy after sunset

• Provide operating reserves

• Support frequency and voltage

• Reduce thermal-plant cycling

• Displace more fossil-fuel generation

• Improve system resilience

The objective should not simply be to install more solar panels. The objective should be to convert Jamaica’s abundant solar resource into dependable electricity that supports the grid throughout the day and night.

A Simple Analogy: Solar Without Storage

One way to understand this challenge is to compare the electricity system to a national water supply system.

Given the intermittency of rainfall no one would design a modern water system that simply pumps water into pipes only at the moment customers require it, with little or no reservoir capacity. It is inherently clear that a reliable water system needs storage in significant quantities. Reservoirs allow water produced during periods of abundance to be held and delivered during periods of high demand, low rainfall, equipment outage, or emergency.

Without storage, a water system becomes a fragile just-in-time system. It will run short during dry periods or peak-use periods unless it is built with much more pumping and production capacity than would otherwise be required. That additional capacity increases cost, complexity, and inefficiency.

The same principle applies to solar on an island electricity grid. Installing large amounts of solar without sufficient battery storage is similar to building a national water supply system without enough reservoirs. The grid is forced to accept renewable energy when it is available, but still requires other generation capacity when solar output falls, demand rises, or the sun sets. In effect, the country pays for solar capacity and must still retain significant fossil-fuel capacity to meet periods of low renewable production and high demand.

Across the Caribbean, planners and procurement processes have often under-specified storage in renewable-energy tenders. This is usually done with good intentions: to reduce upfront project costs and make bids appear more affordable. However, this approach can be misguided if it fails to value the full system benefits that storage provides.

Storage is not merely an added cost. Properly sized storage can reduce the need for additional standby generation, lower spinning-reserve requirements, reduce ramping stress on thermal plants, improve frequency and voltage stability, shift renewable energy into high-demand periods, and allow the grid to use more of the solar energy already being produced.

This issue has become even more important because battery costs have fallen substantially over the last four years. Many integrated resource plans and procurement assumptions across the Caribbean were prepared two to four years ago, or longer. In today’s market, those assumptions may already be outdated.

Technology is changing so quickly that planning tools and integrated resource plans can become obsolete within only a few years of being written. Jamaica and the wider Caribbean therefore need procurement frameworks that reflect current technology costs, current grid needs, and the real value of storage - not assumptions that were reasonable several years ago but no longer reflect the market.

The lesson is simple: if storage is essential for water, it is also essential for high-renewable electricity systems. Solar produces the resource; storage makes that resource reliable.

Retrofitting Storage into Existing Renewable Projects

Jamaica should also consider whether battery energy storage can be retrofitted into the country’s existing solar and wind projects.

The national discussion should not focus only on how future renewable plants are designed. Jamaica already has a substantial fleet of intermittent renewable generation connected to the grid, and its variable output will continue to affect system operations throughout the remaining life of those facilities.Adding appropriately sized battery storage at, or near, existing renewable plants could help convert their fluctuating output into a more stable and predictable supply profile.

Rather than allowing every change in cloud cover or wind speed to pass directly through to the national grid, battery systems could absorb short-term increases in production and release energy when renewable output declines.

This could provide several important benefits:

• Smooth sudden changes in solar and wind generation

• Reduce short-term frequency and voltage disturbances

• Limit the severity of morning and evening ramps

• Improve the predictability of renewable-energy delivery

• Reduce the need for rapid thermal-plant response

• Lower spinning-reserve requirements

• Make better use of existing interconnection infrastructure

• Increase the operational value of renewable plants already paid for by consumers

The objective would not necessarily be to store every megawatt-hour produced by each facility. In some cases, relatively short-duration battery systems could provide significant grid benefits simply by controlling the rate at which output rises or falls.

Larger storage systems could also shift surplus renewable energy into evening periods, reduce curtailment, and allow existing facilities to provide more dependable energy to the system.

A national storage-retrofit programme should therefore evaluate each existing renewable project based on:

• Plant output and historical variability

• Existing interconnection capacity

• Available land and physical space

• Remaining PPA term

• Inverter and control-system compatibility

• Potential reduction in system operating costs

• Required amendments to dispatch and payment arrangements

• The relative benefits of plant-level versus centrally located storage

This evaluation should include Paradise Park, Content Solar, Wigton, BMR Wind, and any other material intermittent generation facility connected to the national grid. In most cases, installing storage directly at an existing plant will be the most effective option. In others, strategically located grid-scale batteries serving several renewable plants or a constrained section of the transmission system may provide greater value.

The important principle is that the output of Jamaica’s existing intermittent renewable fleet should not be treated as fixed and unchangeable. Through storage, modern controls, and revised operating arrangements, the country may be able to improve the performance of assets already in service while preparing the grid for the next phase of renewable development.

Retrofitting storage into existing facilities would not eliminate the need for new firm solar-plus-storage projects. However, it could materially improve the stability of the national

grid, increase the usefulness of existing renewable generation, and reduce the operational challenges created as additional intermittent capacity is added.

From Intermittent Renewable Energy to Firm Renewable Power

Jamaica’s next phase of renewable development must focus on firm and dispatchable renewable energy. That requires a combination of:

• Solar generation

• Appropriately sized battery storage

• Modern control systems

• Geographic diversity

• Strong interconnection planning

• Clear dispatch arrangements

• Retention of efficient thermal backup during the transition

The newest and most efficient natural-gas plants will continue to play an important reliability role, particularly during prolonged periods of poor weather or major system disturbances.

The transition should therefore be carefully managed. But the long-term direction is clear. Renewable energy must evolve from being an intermittent supplement to becoming a dependable part of Jamaica’s core electricity supply.

A Better Question

The question for Jamaica should no longer be: How many additional megawatts of solar can we install?

The better question is: How much reliable renewable energy can we deliver when the country needs it?

That change in perspective is essential. Installed capacity alone will not achieve Jamaica’s renewable target. Solar generation alone will not eliminate fossil-fuel dependence. And intermittent energy alone cannot form the foundation of a reliable island electricity system. Jamaica needs renewable power that is affordable, resilient, and available beyond daylight hours.

That means the next generation of renewable projects must be designed around solar plus storage, not solar alone.

In my next article, I will examine how this approach can support the broader reconstruction of Jamaica’s infrastructure following Hurricane Melissa and why energy resilience must become a central part of the national recovery strategy.

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About This Series

Jamaica’s Energy Future: From Ambition to Action is a five-part series by Emanuel DaRosa, former President and CEO of Jamaica Public Service Company and CEO of SunTerra Energy. The series examines Jamaica’s progress toward its renewable-energy goals, the operational realities of integrating renewable generation into an island electricity system, and the practical steps required to build a more affordable, reliable, resilient, and energy-independent Jamaica.

The articles are intended to contribute to a constructive national discussion involving Government, regulators, utilities, investors, development partners, businesses, energy professionals, academics, and consumers.

The Five-Part Series

Part 1 - Jamaica Is Not on Track to Reach 50% Renewable Energy by 2030: Jamaica’s current renewable-energy position, the scale of the remaining gap, and why the present pace is insufficient.

Part 2 - What Uruguay Can Teach Jamaica About Energy Transformation: How long-term planning, policy certainty, national consensus, and private capital transformed Uruguay’s electricity sector.

Part 3 - Why Solar Alone Will Not Get Jamaica to 50% Renewable Energy: Why installed capacity, annual energy, and firm power are different-and why storage is essential for Jamaica’s grid.

Part 4 - Building a Resilient Energy System for Post-Melissa Jamaica: How national reconstruction can create stronger, geographically diverse, climate-resilient energy infrastructure.

Part 5 - A Practical Roadmap to 50% Renewable Energy - and Why Jamaica Should Not Stop There: A programme-based pathway to 50% and a responsible strategy for moving beyond it while managing LNG commitments.

Readers who encounter the series out of sequence are encouraged to begin with Part 1 and continue through the articles in order, as each builds upon the analysis and conclusions of the previous instalments.

Follow Emanuel DaRosa and SunTerra Energy on LinkedIn for the remaining articles and future discussion on Jamaica’s energy transformation or visit our website: www.sunterra.co