GridValue: Reframing solar-plus-storage economics through the Borehole Battery Platform

The Lazard 2026 Levelized Cost of Energy+ (LCOE+) report reinforces a long-standing view: utility-scale solar remains among the least-expensive sources of new generation, with unsubsidized LCOE roughly $40 to $61 per MWh. Yet two caveats shape today’s analytics. First, firming costs and capacity accreditation matter as much as the raw cost of production. Second, the value of renewable resources is not uniform across regions; reliability frameworks and interconnection constraints can swamp average cost signals. On bright spring afternoons, solar electricity can reach levels where demand or transmission capacity cannot keep pace, driving negative prices and curtailment. The natural response—reducing output—addresses a supply-side constraint but does not reveal what the surplus energy could become. This is where GridValue begins to change the game.

Analytics lens: GridValue as the core metric

GridValue reframes the economics of solar-plus-storage by asking not only what it costs to generate a megawatt-hour, but when and where that megawatt-hour can be delivered and how long it can be sustained. The concept responds to a critical market reality: the value of solar electricity is highly time- and location-dependent, and curtailed energy often carries little immediate revenue, even if it is technically free to produce. By quantifying value streams that arise from absorption of curtailed energy, GridValue converts a curtailment problem into a reliability and capacity opportunity. This analytic stance lines up with Lazard’s emphasis on firming and regional reliability, while expanding the frame to include duration, interconnection, and reuse of existing infrastructure.

Key dimensions within GridValue include:

• Curtailment avoidance and absorption potential across hours of the day and seasons
• Storage duration and the ability to deliver energy during peak or high-value windows
• Dependable-capacity value and the ability to count on energy when the grid needs it most
• Interconnection constraints, brownfield redevelopment potential, and permitting risk
• Safety, supply-chain exposure, useful life, and bankability of deployed assets

In effect, GridValue elevates the strategic value of existing renewable assets by recognizing the marginal utility of hedging against price volatility, reliability shortfalls, and transmission bottlenecks. This is not a radical rejection of LCOE; it is an additive framework that builds on it, acknowledging that the lowest-cost electrons often arrive when the market price is least able to capture their value. The approach is compatible with Lazard’s observation that solar, wind, and storage will dominate near-term capacity additions, but it pushes scrutiny toward how and where those electrons are stored, deployed, and retired as dependable power.

Contrast with conventional thinking

Traditional optimization often starts from the storage device up: what is the cheapest BESS (battery energy storage system) or thermal storage solution, and how many MWh or MW does it deliver? The GridValue perspective flips that logic. It starts from the value of charging electricity—what is the price, availability, and reliability of the energy that would otherwise be curtailed—and then asks how to transform those electrons into deliverable power when the grid needs it. In practice, this yields a different asset mix and a different sequence of investments.

Consider the Borehole Battery Platform (BBP) as a concrete instantiation of GridValue in action. BBP uses curtailed PV to drive a high-temperature heat pump, which compresses and stores energy as heat in repurposed idle oil and gas wells. The storage medium is water in a closed loop, heated to approximately 200°C. When needed, an expander-generator converts the stored heat back into synchronous AC electricity. No natural underground heat is extracted; the wells function as engineered thermal storage vessels charged with electricity. The economic question shifts from “how cheap is the storage device?” to “how valuable is the charging electricity and the later dispatchable heat-driven power?” This reframing aligns with Lazard’s finding that stand-alone storage costs rose in 2026 while the near-zero marginal operating cost of solar remains a strong driver of optimization opportunities, now increasingly contingent on duration and location.

BBP’s logic is not to replace batteries but to complement them by expanding the set of deliverable services. It treats surpluses as a harvester of capacity value rather than a curtailment penalty. From a GridValue standpoint, the critical test is whether the stored energy can be monetized across multiple value streams: firm capacity, peak-power delivery, microgrid resilience, and backup power during outages or price spikes. This multi-revenue potential is where GridValue truly differentiates itself from conventional LCOE-only assessments and why the revenue profile of a curtailed MWh can improve with the right storage approach and regulatory alignment.

Cause and effect: from curtailment to dispatchable power

The causal chain begins with a mismatch between solar generation and grid absorption capabilities. On bright afternoons, PV generation can outstrip demand and transmission capacity, triggering curtailment despite the asset’s technical capability to produce. A conventional response minimizes output; GridValue, by contrast, seeks to monetize the surplus by converting it into a deliverable resource. The BBP chain illustrates this neatly: curtailed solar power becomes electricity that drives a heat pump, which stores energy as heat in idle wells. When demand rises or prices surge, the expander converts the stored heat back into electricity.

Why does this matter economically? Because the value of dispatchable power is higher than the value of a curtailed MWh, even if the energy is initially cheap or free to generate. This is particularly true during evening peaks, cold snaps, or grid emergencies when reliability constraints tighten. The value streams broaden from mere energy to capacity, resilience, and auxiliary services. GridValue, therefore, requires new performance metrics: storage duration, ramp capability, and dependable capacity under interconnection constraints. It also forces a re-examination of project economics in light of potential reuse of brownfield sites, permitting timelines, and safety considerations—factors Lazard flags as central to near-term capacity additions.

The downstream implications are notable. If curtailment avoidance becomes a measurable value, projects that optimize for duration and location can secure higher capacity value credits, better interconnection terms, and stronger bankability. The consequence is a shift in project finance models: more emphasis on long-duration reliability, regulatory risk sharing, and asset portfolio synergies that combine PV, storage, and repurposed infrastructure. GridValue thus acts as a bridge between the physics of solar generation and the economics of grid services, aligning technological feasibility with financial viability.

Expert reconstruction: viability, risks, and deployment paths

From an expert vantage point, GridValue is compelling because it resonates with Lazard’s observed trends and with the structural shifts in how energy storage is valued. The Lazard 2026 LCOE+ report notes that solar and wind, accompanied by storage, are expected to dominate near-term capacity additions due to cost and deployment speed. It also observes that standalone storage costs rose in 2026 after prior declines, while solar’s virtually zero marginal operating cost continues to elevate the strategic importance of optimizing existing renewable assets. GridValue provides the analytical framework to translate those observations into investable pathways by foregrounding duration, location, and reuse of existing infrastructure.

However, the BBP concept does not automatically guarantee lower costs than conventional BESS. The critical uncertainties revolve around engineering, permitting, and integration with grid reliability frameworks. The thermal storage regime—charging energy into wells and later discharging it as electricity—depends on the physical state of the wells, reservoir integrity, and the effectiveness of heat transfer. Regulatory treatment of repurposed wells, safety standards, and interconnection criteria will shape the pace and scale of deployment. GridValue’s value proposition strengthens when the infrastructure stack already exists or can be repurposed with manageable risk, reducing brownfield redevelopment and permitting timelines. In such cases, the combination of curtailed solar, long-duration storage, and flexible dispatch can produce a powerful value proposition for grid operators and regulators alike.

To operationalize GridValue, projects must demonstrate credible performance against a multifactor value score that includes curtailment avoidance, storage duration, dependable capacity, and interconnection feasibility, alongside safety and bankability. Decision-makers should demand transparent modeling that links the charging electricity price with revenue streams across different market regimes and grid conditions. In practice, that means robust scenario analysis, probabilistic risk assessments, and contract designs that incentivize performance across multiple services rather than a single revenue line. If executed with disciplined risk management and regulatory alignment, BBP-inspired projects could complement or even substitute for some conventional storage deployments, particularly in brownfield-rich regions with favorable infrastructure synergies.

In summary, GridValue offers a structured way to quantify the full economic promise of solar plus storage, going beyond the classical LCOE lens. It frames stored energy as a strategic resource that can be time-shifted, capacity-backed, and re-deployed to meet grid needs when they arise. The Borehole Battery Platform is one potential embodiment of this framework, turning excess daytime PV into dispatchable, low-emission power after sunset. The path to widespread adoption will depend on a combination of techno-economic validation, regulatory clarity, and the ability to integrate with existing reliability planning processes. When these conditions align, GridValue could redefine how utilities, developers, and financiers evaluate and deploy solar-plus-storage assets across the United States and beyond.

Ultimately, the goal is not merely to harvest sunlight more cheaply, but to capture its value more reliably. GridValue provides the compass for that journey, guiding investment toward assets and configurations that maximize curtailment avoidance, extend storage duration, and enhance dependable capacity. In this frame, PV is not merely a generator of electrons; it becomes a flexible, value-generating component of a resilient and modern electricity system.

Conclusion-like synthesis (without the term): The combination of Lazard’s cost analysis with GridValue-driven thinking and BBP innovations suggests a future where solar power is not constrained by price alone but augmented by its capacity to be stored and deployed as dependable power. The key is to align project design, regulatory incentives, and market structures so that curtailed energy becomes a core asset in grid reliability rather than a casualty of oversupply.

Operational implications and policy touchpoints

• Tariff and interconnection structures that reward curtailed-energy absorption and long-duration storage
• Permitting regimes that recognize brownfield redevelopment and repurposed wells as legitimate energy storage assets
• Performance-based contracts that credit dependable-capacity value and system resilience
• Grid planning methodologies that incorporate GridValue as a central metric for investment prioritization

As the energy transition accelerates, the imperative to convert every electron into reliable service becomes sharper. GridValue offers a rigorous language for this transition, connecting the dots between the economics of LCOE, the operational realities of curtailment, and the strategic opportunities presented by long-duration storage platforms like BBP. The result is a more nuanced, more resilient, and more valuable solar-plus-storage ecosystem that aligns investor incentives with grid needs in a world of growing variability and tighter reliability standards.

End state ambition: a grid where curtailed solar energy is systematically recaptured, stored, and re-discharged as dispatchable power, enabling deeper penetration of renewables with fewer constraints and greater confidence in reliability. GridValue is the analytical lens that makes that ambition tractable and attractive to market participants across the value chain.

Closing the loop: operationalizing GridValue for solar-plus-storage

To move beyond LCOE-centric thinking, the critical step is to quantify multi-stream value and align with market, grid, and regulatory realities. The Borehole Battery Platform shows how curtailed energy can become dispatchable power, but the economics hinge on revenue stacking, interconnection feasibility, and safety and permitting.

Value streams from curtailed energy

Operational plan: locate BBP near constrained PV sites, stack services in multi-year contracts, and align brownfield opportunities to shorten permitting. A mid-scale pilot can demonstrate achievable duration, ramp, and interconnection reach, building confidence for lenders and regulators.

The practical takeaway is that grids benefit when curtailed energy can be monetized through duration, location, and reuse of existing wells, moving closer to bankable project economics anchored in multi-service revenue rather than a single energy price.