Technological innovation is driving renewable energy towards a future where it is cost competitive without subsidies and provides a growing share of America’s energy. But for all the technical progress made by the clean energy industry, financial innovation is not keeping pace: access to low-cost capital continues to be fleeting, and the industry has yet to tap institutional and retail investors through the capital markets. This is why a bipartisan group in Congress has proposed extending master limited partnerships (MLPs), a financial mechanism that has long driven investment in traditional energy projects, to the clean energy industry.

Last month Senators Chris Coons (D-DE) and Jerry Moran (R-KS) introduced the Master Limited Parity Act (S. 795); Representatives Ted Poe (R-TX), Mike Thompson (D-CA), and Peter Welch (D-VT) introduced companion legislation (H.R. 1696) in the House of Representatives. The bills would allow MLP treatment for renewable energy projects currently eligible for the Sec. 45 production tax credit (PTC) or 48 investment tax credit (ITC) (solar, wind, geothermal, biomass, hydropower, combined heat and power, fuel cells) as well as biofuels, renewable chemicals, energy efficient buildings, electricity storage, carbon capture and storage, and waste-heat-to-power projects. The bill would not change the eligibility of projects that currently qualify as MLPs such as upstream oil and gas activities related to exploration and processing or midstream oil and gas infrastructure investments.

MLPs have been successfully utilized for traditional fossil-fuel projects because they offer an efficient means to raise inexpensive capital. The current total market capitalization of all energy-related MLPs exceeds $400 billion, on par with the market value of the world’s largest publicly traded companies. Ownership interests for MLPs are traded like corporate stock on a market. In exchange for restrictions on the kinds of income it can generate and a requirement to distribute almost all earnings to shareholders (called unitholders), MLPs are taxed like a partnership, meaning that income from MLPs is taxed only at the unitholder level. The absence of corporate-level taxation means that the MLP has more money to distribute to unitholders, thus making the shares more valuable. The asset classes in which MLPs currently invest lend themselves to stable, dividend-oriented performance for a tax-deferred investment; renewable energy projects with long-term off-take agreements could also offer similar stability to investors. And since MLPs are publicly traded, the universe of potential investors in renewable projects would be opened to retail investors.

The paperwork for MLP investors can be complicated, however. Also, investors are subject to rules which limit their ability to offset active income or other passive investments with the tax benefits of an MLP investment. Despite the inherent restrictions on some aspects of MLPs, the opportunities afforded by the business structure are generating increasing interest and support for the MLP Parity Act.

Proponents of the MLP Parity Act envision the bill as a way to help renewable energy companies access lower cost capital and overcome some of the limitations of the current regime of tax credits. Federal tax incentives for renewable energy consist primarily of two limited tools: tax credits and accelerated depreciation rates. Unless they have sizeable revenue streams, the tax credits are difficult for renewable project developers to directly use. The reality is only large, profitable companies can utilize these credits as a means to offset their income. For a developer who must secure financing though a complicated, expensive financing structure, including tax equity investors can be an expensive means to an end with a cost of capital sometimes approaching 30%. Tax credits are a known commodity, and developers are now familiar with structuring tax equity deals, but the structure is far from ideal. And as renewable energy advocates know all too well, the current suite of tax credits need to be extended every year. MLP treatment, on the other hand, does not expire.

Some supporters have noted that clean energy MLPs would “democratize” the industry because private retail investors today have no means to invest in to any meaningful degree in clean energy projects. Having the American populace take a personal, financial interest in the success of the clean energy industry is not trivial. The initial success of ‘crowd-funded” solar projects also provides some indication that there is an appetite for investment in clean energy projects which provide both economic and environmental benefits.

Sen. Coons has assembled a broad bipartisan coalition, including Senate Finance Energy Subcommittee Chair Debbie Stabenow (D-MI) and Senate Energy and Natural Resources Ranking Member Lisa Murkowski (R-AK). Republican and Democratic cosponsors agree that this legislation would help accomplish the now-familiar “all-of-the-above” approach to energy policy.

However, some renewable energy companies that depend on tax credits and accelerated depreciation are concerned that Republican supporters of the legislation will support the bill as an immediate replacement for the existing (but expiring) suite of renewable energy tax credits. Sen. Coons does not envision MLP parity as a replacement for the current production tax credits and investment tax credits but rather as additional policy tool that can address, to some degree, the persistent shortcomings of current financing arrangements. In this way, MLPs could provide a landing pad for mature renewable projects as the existing regime of credits is phased out over time, perhaps as part of tax reform.

So would the clean energy industry utilize MLP structures if Congress enacts the MLP Parity Act? The immediate impact may be hard to predict, and some in renewable energy finance fear MLP status will be less valuable than the current tax provisions. This is in part because the average retail investor would not be able to use the full share of accompanying PTCs, ITCs, or depreciation unless Congress were also to change what are known as the “at-risk” and “passive activity loss and tax credit” rules. These rules were imposed to crack down on perceived abuse of partnership tax shelters and have tax implications beyond the energy industry. Modifying these rules is highly unlikely and would jeopardize the bipartisan support the bill has attracted so far. But other renewable energy companies believe they can make the structure work for them now, and industries without tax credits — like renewable chemicals, for instance — would not have the same concerns with “at-risk” and “passive activity loss” rules. Furthermore, over the long term, industry seems increasingly confident the structure would be worthwhile. Existing renewable projects that have fully realized their tax benefits and have cleared the recapture period could be rolled up into existing MLPs. Existing MLP infrastructure projects could deploy renewable energy assets to help support the actual infrastructure. Supporters of the legislation see the change as a starting point, and the ingenuity of the market will find ways to work within the rules to deliver the maximum benefit.

The future of the MLP Parity Act will be linked to the larger conversation in Congress regarding tax reform measures. The MLP Parity Act is not expected to pass as a stand-alone bill; if it were to be enacted, it would most likely be included as part of this larger tax-reform package. Congress currently is looking at ways to lower overall tax rates and modify or streamline technology-specific energy provisions. This has many renewable energy advocates on edge: while reform provides an opportunity to enact long-term policies (instead of one-year extensions) that could provide some level of stability, it also represents a chance for opponents of renewable energy to exact tough concessions or eliminate existing incentives. As these discussions continue in earnest this year, the reintroduction of the MLP Parity Act has already begun to generate discussions and mentions in policy white papers at both the House Ways and Means Committee and the Senate Finance Committee. Whether a highly partisan Congress can actually achieve such an ambitious goal as tax reform this year remains uncertain. But because of its bipartisan support, the MLP Parity Act certainly will be one of the many potential reforms Congress will consider seriously.