Image: Renalfa
According to experts, this may lead to the fact that in the near future half of the investors will go bankrupt simply because they have no one to sell the “green” energy produced. It is not needed during the day, and at night, when there is demand, photovoltaic systems do not work.
One way out is the use of battery-based energy storage systems (BESS, Battery Energy Storage Systems).
The director of Wolf Theiss Bucharest, Adina Aurel, a manager with 20 years of experience in renewable energy, told SeeNews how these systems have worked in Romania.
An attractive asset
Battery-based energy storage systems are emerging as one of the most attractive asset classes in the energy transition. The rapid development of renewable energy in Romania and the updated regulatory framework for BESS investments create favorable conditions for energy storage projects in both hybrid and off-grid configurations.
The Romanian energy storage market offers two main investment models:
– Hybrid BESS integrated with solar or wind power plants.
– Stand-alone BESS, providing services at system level.
While both models benefit from a growing renewable energy market and favorable regulation, they differ significantly in revenue mix, risk exposure, and operating strategies.
Hybrid systems tend to offer stable returns with less volatility, while stand-alone systems offer higher but more market-dependent returns.
Hybrid BESS
The yield characteristics of a hybrid energy storage system are as follows:
The project provides stable and more predictable returns as the battery increases the value of electricity sold, optimizes its use, and supports more stable renewable energy generation.
By storing energy and selling it during peak price periods, the project can increase revenues while avoiding most market price fluctuations.
The project is less susceptible to market price fluctuations because it profits mainly from long-term fixed-price agreements.
Increased asset utilization efficiency, which means that the hybrid energy storage project makes more efficient use of the solar/wind farm and grid connection point, reducing losses and increasing both monetized generation and revenues.
System-level BESS
In terms of return on investment in off-grid energy storage systems, the potential is greater. The project can profit from several market activities such as balancing services, system operator support and price arbitrage.
Note that revenue depends on market activity, price volatility and procurement requirements of the transmission system operator.
Diversified revenue streams are also possible, although total revenue may vary depending on market conditions.
What investors need to consider
From the perspective of an international investor considering Romania as a location to raise new capital, a number of fundamental issues arise. When evaluating the opportunity to acquire a project from a Romanian developer, investors typically look for a clear and structured set of metrics to assess the feasibility, transparency and long-term potential of the project.
Hybrid BESSs are more suitable for those seeking the predictable returns typical of infrastructure projects.
Attractive to utilities, private energy companies with established renewable energy portfolios or corporate customers.
Particularly valuable in markets with grid congestion or pronounced intraday fluctuations due in part to price spikes during certain hours.
Standalone BESS are suitable for investors with a higher risk tolerance, energy market experience or the ability to trade actively.
Appropriate for infrastructure funds seeking higher yields and diversified income structures.
Ideal for markets with significant balancing needs, incentives driven by transmission grid operators or volatile spot prices.
Hybrid projects tend to offer more stable and less risky returns as storage systems support renewable generation and smooth revenue streams.
Standalone systems can offer higher returns but are more subject to market dynamics, making them more suitable for investors prepared for operational complexity and price volatility.
What about Moldova?
In Moldova, a tender for the procurement of BESS systems was launched by the Ministry of Energy in January 2025, supported by an $85 million grant from the United States. The winner was the American company Tetra Tech, which has been implementing various energy projects in Moldova for two years.
But proposals for industrial energy storage systems from other companies are also appearing on the market. For example, 258 kW from SOLBERG.
Now all tenders held by the Ministry of Energy for potential producers of “green” energy include BESS as a prerequisite.
In other words, Moldova is still only beginning to develop this very important segment of renewable energy. We think that the Romanian experience will be very useful here.
