Plug Power (PLUG) 8-K Results of Operations and Financial Condition

Exhibit 99.1

Second Quarter 2019 Recap: Record Second Quarter Deployments for the Company • Company deployed over 2,000 GenDrive units, up approximately 70% year-over-year, and reported gross billings of $58.6 million, up 50% year-over-year Revenue growth is generating operating leverage; operating income (loss) improved by over 46% for Q2 compared to prior year and adjusted EBITDA was positive for the second quarter 2019 Expanded into on-road vehicle applications, significantly expanding the total addressable market Secured first commercial-scale deployment of ProGen fuel cells for on-road logistics with StreetScooter, a subsidiary of DHL Completed “tuck-in” small scale hydrogen fuel cell technology acquisition to complement suite of offerings for broader logistics, robotics, and UAV markets Hosting Plug Power Symposium in September 2019 • • • • • 1 Guidance 2H-19 FY-2019 Gross Billings $154–$164M $235-$245M Results (millions except EPS) Q2’19 Q2’18 Gross Billings $58.6 $39.2 GAAP Gross Profit (Loss) $10.2 ($2.3) Operating Income (Loss) ($12.4) ($23.0) Adjusted EBITDA $0.1 ($13.5) GAAP EPS ($0.08) ($0.12)

Q2 2019: Record Quarter Reflects Strong Business Momentum The Company deployed over 2,000 GenDrive fuel cell systems to new and recurring customers, including Amazon, Walmart, Bridgestone and Lipari. We are pleased to report substantial improvement in operating margin and adjusted EBITDA. This improvement is both year-over-year, and on a sequential basis. This underscores inherent operating leverage in our business model; at a quarterly gross billing run rate of about $60M, we are break-even at our current cost structure. In addition, ongoing cost reductions continue to lower this threshold. We remain focused on improving our overall profitability as we continue to grow our customer deployments. Increased volume drives operating and manufacturing leverage and enables greater purchasing power in our supply chain. In addition, our engineering team’s design enhancements that improve reliability and reduce cost will improve service and product margins. Strategically, the Company is evaluating ways to turn hydrogen into an accretive cash flow generating business over time and improve margins in our fuel product line. We encourage investors to remain focused on the Company’s long-term strategic priorities and track progress by our overall revenue ramp, margin expansion in material handling, and market expansion into on-road vehicle applications. Reiterating Full Year Guidance: We reiterate our full year 2019 gross billing guidance of $235-$245M. Operating income (loss) for the full year is expected to significantly improve year over year, and we expect positive adjusted EBITDA for the full year 2019 (when you exclude non-cash charges for customer warrant charges). It is important to note the traditional seasonality of our business. One-third of revenue is typically recognized in the first half of the year, and two-thirds during the second half. Business momentum remains strong in material handling, our first large and growing target market. We remain focused on providing an economic and sustainable value proposition to end customers while improving overall margins through cost reduction and other ongoing initiatives. 2

SecondQuarterHighlights:AcceleratingGrowthwithUnfolding Vehicle Electrification Before we begin discussing some of our key accomplishments during the second quarter, just a quick recap on the Company. Plug Power is the leading manufacturer of hydrogen fuel cell engines and fueling stations serving the broader logistics and transportation market. We are the world’s largest buyer of liquid hydrogen fuel, surpassing NASA. We have deployed over 28,000 fuel cell systems and have unmatched field experience on our technology platform with over 200M hours of customer operation. Our modular ProGen hydrogen engines, ranging in size from 10 kW to 200 kW, provide distinct advantages over battery electric vehicles (BEVs), especially in applications which require high-asset utilization, long range, and fast fueling. Based on Plug Power’s best-in-class ProGen metal stack technology, this product line is ideal for asset-intense logistics and transportation applications. In fact, Plug Power is the only company today that can service the entire logistics and transportation market with our modular hydrogen fuel cell engines and fueling stations as a single-sourced vendor. 3

Now, let us provide a quick recap of some of our key Q2 accomplishments. First and foremost, we are pleased with our record second quarter deployments and gross billings; coupled with substantial improvement in operating income (loss) and adjusted EBITDA. Expanding our markets, we announced our first major on-road customer win. In the second quarter, Plug Power closed a deal with electric vehicle manufacturer StreetScooter, a subsidiary of DHL, the world’s largest logistics and mail communications service. With this partnership, StreetScooter will initially deliver 100 ProGen hydrogen fuel cell-powered trucks for on-road use to Deutsche Post DHL, starting in 2020. This marks the world’s first commercial scale fuel cell engine deployment for the on-road logistics application. 4

The ProGen engine provides the StreetScooter van with increased drive time — without the need for long charge hours — and improved efficiency through clean and sustainable technology. Additionally, the fuel cell vehicles will have an effective range covering distances of up to 500 km, approximately doubling the range of the current BEV version. For commercial fleet vehicles, fuel cell engines have minimal impact on cargo space or payload when compared to similar BEVs. 5

According to Markus Reckling, the head of German operations at DHL Express: “If everything works as we imagine it would, there could soon be 500 vehicles worldwide." He further added that 80-90% of last-mile delivery would likely be a hybrid system including batteries and fuel cells. Plug Power has begun manufacturing of the StreetScooter ProGen systems delivery prior to year-end. in its Latham, NY headquarters and expects to begin Plug Power acquired EnergyOr during the second quarter. EnergyOr, based in Montreal Canada, specializes in ultra-lightweight compact PEM hydrogen fuel cell systems. This acquisition allows Plug Power to expand its ProGen suite to address robotics, small-scale material handling, and UAV applications. Industry activity levels remain robust on the commercial and policy fronts. On the commercial front, a major diesel engine manufacturer made a strategic acquisition to enter the fuel cell sector. We view this as a solid positive for the sector. This should help the industry continue to come down the cost curve and accelerate scaling of the supply chain. On the policy front, the Governor of New York, Andrew Cuomo, announced plans 6

to achieve a carbon free grid by 2040 and reduce green-house gas emissions by 85% from 1990 by 2050, making it one of the most aggressive GHG emission goals in the world. We are also delighted to see Senator Maria Cantwell’s (WA) introduction of the FAST Electricity Act that specifically calls for 30% federal tax credit for hydrogen fueling stations, with a phase down in 2025. Coming back to PLUG, both from a near-term and long-term strategy standpoint, we remain focused on growing our business in the core material handling industry and expanding into on-road applications as a comprehensive solution provider in the broader logistics and transportation industry. From our leading position as the largest buyer of liquid hydrogen, the Company is evaluating strategic priorities for the growing hydrogen business. Our interest is twofold: 1) provide increasing comfort of hydrogen price and supply stability to our end customers, and 2) improve margins in this business. Operationally, we remain focused on continuously reducing our product cost, enhancing our technology platform, and increasing overall reliability. These collective activities allow Plug Power to expand the addressable market and continue overall margin improvement. Summary We are on track to deliver over a 10-fold increase in gross billings since 2013 (given 2019 expectations of $235-$245M). We remain focused on delivering growth and expanding addressable markets. With ongoing operational efforts and inherent leverage in the model, this should translate into continuous improvements in overall margins and profitability. This record second quarter highlights the continued traction in our existing material handling market, while the StreetScooter contract validates our market expansion into on-road market applications. As a reminder, we have reduced cost by over 70% in the last 10 years, have accumulated in excess of 200M hours of field runtime, and believe we can reduce our overall cost by 25% as we double our volumes in the near term. Now on to the four major announcements that we spoke about during the beginning of the year: StreetScooter represents the first deal to be made public of the four major announcements, which we shared during the second quarter. We are pleased with ongoing progress and expect to make additional announcements during Q3 at or prior to the September “Plug Power Symposium”. 7

The Company will be hosting this symposium to discuss pertinent issues and topics that will help accelerate the growth of the industry. At the two-day (invitation-only) event, participants will hear from major players in the industry throughout the value chain, policymakers, as well as investors looking to allocate capital in the sector. We look forward to providing a detailed overview of the Company’s growth outlook and strategic priorities. We look forward to sharing our progress for the reminder of the year. Andrew Marsh, President and CEO Paul Middleton, Chief Financial Officer Conference Call Information The Company will host a live conference call and webcast today, August 6, 2019. • • Time: 10:00 am ET Toll-free: 877-407-9221 The webcast can be accessed at www.plugpower.com, selecting the conference call link on the home page, or directly at https://event.webcasts.com/starthere.jsp?ei=1254072&tp_key=2ee473b052. 8

About Plug Power Inc. The architect of modern hydrogen and fuel cell technology, Plug Power is the innovator that has taken hydrogen and fuel cell technology from concept to commercialization. Plug Power has revolutionized the material handling industry with its full-service GenKey solution, which is designed to increase productivity, lower operating costs and reduce carbon footprints in a reliable, cost-effective way. The Company’s GenKey solution couples together all the necessary elements to power, fuel and serve a customer. With proven hydrogen and fuel cell products, Plug Power replaces lead acid batteries to power electric industrial vehicles, such as the lift trucks customers use in their distribution centers. Extending its reach into the on-road electric vehicle market, Plug Power’s ProGen platform of modular fuel cell engines empowers OEMs and system integrators to rapidly adopt hydrogen fuel cell technology. ProGen engines are proven today, with thousands in service, supporting some of the most rugged operations in the world. Plug Power is the partner that customers trust to take their businesses into the future. www.plugpower.com. Cautionary Note on Forward Looking Statements This communication contains "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995 that involve significant risks and uncertainties about Plug Power Inc.("PLUG"), including but not limited to statements about PLUG's expectations regarding growth in profitability and service and product margins, progress and expansion in the electric vehicle market, projected size of addressable markets, cost reductions and volume growth, and H2 and full year 2019 guidance, including gross billings, operating income (loss), and adjusted EBITDA. You are cautioned that such statements should not be read as a guarantee of future performance or results, and will not necessarily be accurate indications of the times that, or by which, such performance or results will have been achieved. Such statements are subject to risks and uncertainties that could cause actual performance or results to differ materially from those expressed in these statements. In particular, the risks and uncertainties include, among other things, the risk that we continue to incur losses and might never achieve or maintain profitability; the risk that we will need to raise additional capital to fund our operations and such capital may not be available to us; the risk that our lack of extensive experience in manufacturing and marketing products may impact our ability to manufacture and market products on a profitable and large-scale commercial basis; the risk that unit orders will not ship, be installed and/or converted to revenue, in whole or in part; the risk that pending orders may not convert to purchase orders, in whole or in part; the risk that a loss of one or more of our major customers could result in a material adverse effect on our financial condition; the risk that a sale of a significant number of shares of stock could depress the market price of our common stock; the risk that negative publicity related to our business or stock could result in a negative impact on our stock value and profitability; the risk of potential losses related to any product liability claims or contract disputes; the risk of loss related to an inability to maintain an effective system of internal controls or key personnel; the risks related to use of flammable fuels in our products; the cost and timing of developing, marketing and selling our products and our ability to raise the necessary capital to fund such costs; the ability to achieve the forecasted gross margin on the sale of our products; the risk that our actual net cash used for operating expenses may exceed the projected net cash for operating expenses; the cost and availability of fuel and fueling infrastructures for our products; market acceptance of our products, including GenDrive, GenSure and GenKey systems; the volatility of our stock price; our ability to establish and maintain relationships with third parties with respect to product development, manufacturing, distribution and servicing and the supply of key product components; the cost and availability of components and parts for our products; our ability to develop commercially viable products; our ability to reduce product and manufacturing costs; our ability to successfully expand our product lines; our ability to successfully expand internationally; our ability to improve system reliability for our GenDrive, GenSure and GenKey systems; competitive factors, such as price competition and competition from other traditional and alternative energy companies; our ability to protect our intellectual property; the cost of complying with current and future federal, state and international governmental regulations; risks associated with potential future acquisitions; and other risks and uncertainties referenced in our public filings with the Securities and Exchange Commission (the “SEC”). For additional disclosure regarding these and other risks faced by PLUG, see disclosures contained in PLUG's public filings with the SEC including, the "Risk Factors" section of PLUG's Annual Report on Form 10-K for the year ended December 31, 2018. You should consider these factors in evaluating the forward-looking statements included in this presentation – vs. communication and not place undue reliance on such statements. The forward-looking statements are made as of the date hereof, and PLUG undertakes no obligation to update such statements as a result of new information. Plug Power Contact Teal Vivacqua Hoyos 518.738.0269 plugpower@pluckpr.com SOURCE: PLUG POWER 9

Plug Power Inc. and Subs idiaries Condens ed Cons olidated Balance Sheets (In thous ands , except s hare and per s hare amounts ) (Unaudited) June 30, 2019 December 31, 2018 As s ets Current as s ets : Cas h and cas h equivalents Res tricted cas h Accounts receivable Inventory Prepaid expens es and other current as s ets Total current as s ets $ 19,845 19,400 26,592 73,190 $ 38,602 17,399 37,347 47,910 14,001 14,357 153,028 155,615 Res tricted cas h Property, plant, and equipment, net of accumulated depreciation of $15,882 and $14,403, res pectively Leas ed property, net Goodwill Intangible as s ets , net Other as s ets Total as s ets 96,082 14,228 170,455 8,961 5,398 8,842 54,152 12,869 146,751 9,023 3,890 8,026 $ 456,994 $ 390,326 Liabilities , Redeemable Preferred Stock, and Stockholders ’ (Deficit) Equity Current liabilities : Accounts payable Accrued expens es Deferred revenue Finance obligations Current portion of long-term debt Other current liabilities Total current liabilities Deferred revenue Common s tock warrant liability Finance obligations Convertible s enior notes , net Long-term debt Other liabilities Total liabilities $ 36,946 4,522 11,730 30,663 15,928 $ 34,824 7,864 12,055 74,264 16,803 3,017 560 102,806 24,519 525 157,531 66,844 83,776 13 146,370 28,021 105 118,076 63,247 133 18 436,014 355,970 Redeemable preferred s tock: Series C redeemable convertible preferred s tock, $0.01 par value per s hare (aggregate involuntary liquidation preference $16,664); 10,431 s hares authorized; Is s ued and outs tanding: 2,620 at both June 30, 2019 and December 31, 2018 Series E redeemable convertible preferred s tock, $0.01 par value per s hare (aggregate involuntary liquidation preference $35,000 at both June 30, 2019 and December 31, 2018); Shares authorized: 35,000 at both June 30, 2019 and December 31, 2018; Is s ued and outs tanding: 35,000 at June 30, 2019 and December 31, 2018 Stockholders ’ (deficit) equity: Common s tock, $0.01 par value per s hare; 750,000,000 s hares authorized; Is s ued (including s hares in treas ury): 246,975,173 at June 30, 2019 and 234,160,661 at December 31, 2018 Additional paid-in capital Accumulated other comprehens ive income Accumulated deficit Les s common s tock in treas ury: 15,020,437 at June 30, 2019 and 15,002,663 at December 31, 2018 Total s tockholders ’ (deficit) equity Total liabilities , redeemable preferred s tock, and s tockholders ’ (deficit) equity 709 709 30,926 30,934 2,470 1,328,911 1,460 (1,312,815) (30,681) 2,342 1,289,714 1,584 (1,260,290) (30,637) (10,655) 2,713 $ 456,994 $ 390,326 10

Plug Power Inc. and Subs idiaries Condens ed Cons olidated Statement of Operations (In thous ands , except s hare and per s hare amounts ) (Unaudited) Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Net revenue: Sales of fuel cell s ys tems and related infras tructure Services performed on fuel cell s ys tems and related infras tructure Power Purchas e Agreements Fuel delivered to cus tomers Net revenue Cos t of revenue: Sales of fuel cell s ys tems and related infras tructure Services performed on fuel cell s ys tems and related infras tructure Power Purchas e Agreements Fuel delivered to cus tomers Total cos t of revenue $ 38,547 5,282 6,307 $ 18,820 5,691 5,438 $ 40,767 11,495 11,014 $ 29,433 11,174 10,810 6,932 5,280 12,385 10,230 57,068 35,229 75,661 61,647 23,129 6,218 8,713 8,854 15,377 6,103 9,638 6,421 25,450 12,341 17,711 16,775 25,499 11,837 18,288 12,317 46,914 37,539 72,277 67,941 Gros s profit (los s ) 10,154 (2,310) 3,384 (6,294) Operating expens es : Res earch and development Selling, general and adminis trative Total operating expens es 8,933 13,627 8,427 12,241 16,306 22,951 17,075 20,550 22,560 20,668 39,257 37,625 Operating los s (12,406) (22,978) (35,873) (43,919) Interes t and other expens e, net Change in fair value of common s tock warrant liability (7,861) 1,706 (6,136) 334 (16,206) (420) (9,241) 1,592 Los s before income taxes $ (18,561) $ (28,780) $ (52,499) $ (51,568) Income tax benefit — 2,912 — 5,865 Net los s attributable to the Company $ (18,561) $ (25,868) $ (52,499) $ (45,703) Preferred s tock dividends declared and accretion of dis count (26) (13) (26) (26) Net los s attributable to common s hareholders $ (18,587) $ (25,881) $ (52,525) $ (45,729) Net los s per s hare: Bas ic and diluted $ (0.08) $ (0.12) $ (0.23) $ (0.21) Weighted average number of common s hares outs tanding 231,114,868 214,315,312 225,899,224 220,650,537 11

Plug Power Inc. and Subs idiaries Condens ed Cons olidated Statement of Cas h Flows (In thous ands ) (Unaudited) Six months ended June 30, 2019 2018 Operating Activities Net los s attributable to the Company Adjus tments to reconcile net los s to net cas h us ed in operating activities : Depreciation of property, plant and equipment, and leas ed property Amortization of intangible as s ets Stock-bas ed compens ation Provis ion for bad debts and other Amortization of debt is s uance cos ts and dis count on convertible s enior notes Provis ion for common s tock warrants Change in fair value of common s tock warrant liability Los s on dis pos al of leas ed as s ets Income tax benefit Changes in operating as s ets and liabilities that provide (us e) cas h: Accounts receivable Inventory Prepaid expens es and other as s ets Accounts payable, accrued expens es , and other liabilities Deferred revenue Net cas h us ed in operating activities Inves ting Activities Purchas es of property, plant and equipment Purchas es of intangible as s ets Purchas es for cons truction of leas ed property Proceeds from s ale of leas ed as s ets Net cas h us ed in inves ting activities $ (52,499) $ (45,703) 5,496 338 5,123 907 4,340 5,662 420 212 — 5,795 335 4,325 — 2,438 5,806 (1,592) — (5,865) 9,848 (25,280) (460) 1,232 (3,827) (16,178) 6,488 1,556 (6,685) 4,101 (48,488) (45,179) (2,844) (1,860) (1,987) 375 (2,343) (879) (13,138) — (6,316) (16,360) Financing Activities Proceeds from is s uance of preferred s tock, net of trans action cos ts Proceeds from public offerings , net of trans action cos ts Proceeds from exercis e of s tock options Proceeds from is s uance of convertible s enior notes , net Purchas e of capped call and common s tock forward Principal payments on long-term debt Proceeds from long-term debt Proceeds from s ale/leas eback trans actions accounted for as finance leas es Repayments of finance obligations Increas e in finance obligations Net cas h provided by financing activities Effect of exchange rate changes on cas h Increas e (decreas e) in cas h, cas h equivalents and res tricted cas h Cas h, cas h equivalents , and res tricted cas h beginning of period Cas h, cas h equivalents , and res tricted cas h end of period (8) 28,265 205 — — (17,521) 99,546 — (56,070) 25,609 — — 67 95,856 (43,500) (5,721) — 20,000 (17,760) — 80,026 48,942 (48) (36) 25,174 110,153 (12,633) 68,055 $ 135,327 $ 55,422 Supplemental dis clos ure of cas h flow information Cas h paid for interes t $ 8,673 $ 4,915 Summary of non-cas h inves ting and financing activity Recognition of right of us e as s et $ 34,530 $ 2,513 12

Plug Power Inc. Reconciliation of Non-GAAP Financial Meas ures (Dollars in 000's ) For the three months ended June 30, For the s ix months ended June 30, Reconciliation of Reported Operating Los s to Adjus ted EBITDA 2019 2018 2019 2018 Operating los s , as reported Stock-bas ed compens ation (1) Depreciation and amortization (2) Right-of-us e as s et depreciation and interes t as s ociated with PPA financings ( 3) Res tructuring and other non-recurring charges Adjus ted EBITDA $ (12,406) 2,626 2,882 6,190 812 $ (22,978) 2,320 3,192 3,628 300 $ (35,873) 5,123 5,834 12,149 1,981 $ (43,919) 4,325 6,130 7,171 778 $ 104 $ (13,538) $ (10,786) $ (25,515) Non-GAAP Measure To s upplement the Company’s unaudited financial data pres ented on a generally accepted accounting principles (GAAP) bas is , management has us ed adjus ted EBITDA, which is a non-GAAP meas ure. Adjus ted EBITDA is defined as operating los s , as reported, plus s tock-bas ed compens ation, plus depreciation and amortization, plus right-of-us e as s et depreciation and interes t as s ociated with PPA financings , plus res tructuring and other non-recurring charges . This non-GAAP meas ure is an indicator management us es as a bas is for evaluating the Company’s performance as well as for forecas ting future periods . Management als o es tablis hes performance targets , annual budgets and makes operating decis ions bas ed in part upon adjus ted EBITDA. Dis clos ure of this non-GAAP meas ure provides inves tors with the s ame information that management us es for thes e purpos es . In addition, inves tors have his torically reques ted and the Company has his torically reported this non-GAAP financial meas ure as a means of providing cons is tent and comparable information with pas t reports of financial res ults . Adjus ted EBITDA is not a meas ure of our performance under GAAP and s hould not be cons idered in is olation or as an alternative to reported operating income (los s ) or any other meas ures prepared in accordance with GAAP. While management believes that adjus ted EBITDA provides us eful s upplemental information to inves tors , there are limitations as s ociated with the us e of this meas ure. Adjus ted EBITDA is not prepared in accordance with GAAP and may not be directly comparable to a s imilarly titled meas ure of other companies due to potential differences in the exact method of calculation. Adjus ted EBITDA s hould be read only in conjunction with the Company’s cons olidated financial s tatements prepared in accordance with GAAP. Notes (1) Repres ents employee compens ation in the form of the Company's s tock or s tock-bas ed awards . (2) Repres ents depreciation and amortization expens e related to the Company's fixed as s ets and intangibles . (3) Repres ents right-of-us e as s et depreciation and interes t as s ociated with operating leas es . The right-of-us e as s et depreciation and interes t expens e as s ociated with operating leas es is calculated in accordance with ASC Topic 842, and is equal to operating leas e expens e during any given reporting period. 13