No statistical methods were used to predetermine sample size. The experiments were not randomized and investigators were not blinded to allocation during experiments and outcome assessment. The human iPS cell lines 201B7, 253G1, and 454E2 were obtained from the RIKEN Bio Resource Center (Tsukuba, Japan)21, 22. The 1231A3 and 1383D2 human iPS cells were provided by the Center for iPS Cell Research and Application, Kyoto University23. All cells were cultured in StemFit medium (Ajinomoto, Tokyo, Japan) on LN511E8-coated (0.5 μg cm−2) dishes23, 24. LN511E8, produced using cGMP-banked CHO-S cells (Life Technologies, Carlsbad, CA), was obtained from Nippi (Tokyo, Japan). In part, LN511E8 was produced using human 293-F cells as previously described12. The 201B7 and 454E2 human iPS cell lines were used in the in vitro experiments, while 201B7 and 1383D2 cells were used in the animal experiments; 253G1 and 1231A3 cells were used in the supplementary experiments, the results of which are reported in Extended Data Fig. 7. All of the experiments using recombinant DNA were approved by the Recombinant DNA Committees of Osaka University and were performed according to our institutional guidelines. The differentiation culture for human iPS cells was performed as indicated in Fig. 3a. First, human iPS cells were seeded on LN511E8-coated dishes at 350–700 cells cm−2, after which they were cultivated in StemFit medium for 8–12 days. The culture medium was then changed to DM (differentiation medium; GMEM (Life Technologies) supplemented with 10% knockout serum replacement (KSR; Life Technologies), 1 mM sodium pyruvate (Life Technologies), 0.1 mM non-essential amino acids (Life Technologies), 2 mM l-glutamine (Life Technologies), 1% penicillin-streptomycin solution (Life Technologies) and 55 μM 2-mercaptoethanol (Life Technologies) or monothioglycerol (Wako, Osaka, Japan))25. In some experiments, as indicated in the Results section, Noggin (R&D systems, Minneapolis, MN), LDN-193189 (Wako) or SB-431542 (Wako) were added for the first four days. BMP4 (R&D systems) was used in some early experiments at concentrations up to 0.125 nM. This had no discernible effect on SEAM formation, however, so its use was discontinued. After four weeks of culture in DM, the medium was changed to corneal differentiation medium (CDM; DM and Cnt-20 or Cnt-PR (w/o; EGF and FGF2) (1:1, CELLnTEC Advanced Cell Systems, Bern, Switzerland) containing 5 ng ml−1 FGF2 (Wako), 20 ng ml−1 KGF (Wako) 10 μM Y-27632 (Wako) and 1% penicillin-streptomycin solution). FGF2 in CDM was not essential for corneal epithelial induction. During CDM culture (around six to eight weeks of differentiation), non-epithelial cells were removed by manual pipetting under microscopy (Extended Data Fig. 2a, b). After pipetting, the medium was changed to fresh CDM. After four weeks of culture in CDM, the medium was changed to corneal epithelium maintenance medium (CEM; DMEM/F12 (2:1), Life Technologies) containing 2% B27 supplement (Life Technologies), 1% penicillin-streptomycin solution, 20 ng ml−1 KGF and 10 μM Y-27632 for two to seven weeks. To achieve retinal differentiation (Fig. 2c) after four weeks of differentiation the medium was directly changed to CEM. Isolated RPE cell colonies were cultivated in CEM on separate dishes coated with LN511E8. Phase-contrast microscopic observations were performed with an Axio-observer.Z1, D1 (Carl Zeiss, Jena, Germany) and an EVOS FL Auto (Life Technologies). Differentiated human iPS cells in CEM were dissociated using Accutase (Life Technologies), and resuspended in ice-cold KCM medium (DMEM without glutamine and Nutrient Mixture F-12 Ham (3:1, Life Technologies) supplemented with 5% FBS (Japan Bio Serum, Hiroshima, Japan), 0.4 μg ml−1 hydrocortisone succinate (Wako), 2 nM 3,3′,5-Triiodo-l-thyronine sodium salt (MP biomedicals, Santa Ana, CA), 1 nM cholera toxin (List Biological Laboratory, Campbell, CA), 2.25 μg ml−1 bovine transferrin HOLO form (Life Technologies), 2 mM l-glutamine, 0.5% insulin transferrin selenium solution (Life Technologies) and 1% penicillin-streptomycin solution). The harvested cells were filtered with a cell strainer (40 μm, BD Biosciences, San Diego, CA) and then stained with anti-SSEA-4 (MC813-70, Biolegend, San Diego, CA), TRA-1-60 (TRA-1-60-R, Biolegend) and CD104 (ITGB4; 58XB4, Biolegend) antibodies for 1 h on ice. After being washed twice with PBS, stained cells underwent cell sorting with a FACSAria II instrument (BD Biosciences). For intracellular protein staining, a BD Cytofix/Cytoperm (BD Biosciences) kit was used. In all of the experiments, cells were stained with non-specific isotype IgG or IgM as controls (Biolegend). The data were analysed using the BD FACSDiva Software (BD Biosciences) and the FlowJo software program (TreeStar, San Carlos, CA). Sorted human iPS cell-derived epithelial cells obtained from zone 3 of the SEAM (human iCECs) were seeded on LN511E8 coated (0.5 μg cm−2) cell culture inserts or temperature-responsive dishes (UpCell, CellSeed, Tokyo, Japan) without cell passaging, and were cultured in CEM until confluence26. To promote maturation, the epithelial cells were cultivated in CMM (corneal epithelium maturation medium; KCM medium containing 20 ng ml−1 KGF and 10 μM Y-27632) for an additional 3–14 days after CEM culture. The human iCECs cultivated on temperature-responsive dishes were released from their substrate by reducing the temperature to 20 °C. Total RNA was obtained from differentiated human iPS cells after specific culture periods, from human epidermal keratinocytes (EKs (foreskin), Life Technologies and TaKaRa Bio, Otsu, Japan), and from human corneal limbal epithelial cells (CECs) using the RNeasy total RNA kit or the QIAzol reagent (Qiagen, Valencia, CA). Reverse transcription was performed using the SuperScript III First-Strand Synthesis System for qRT–PCR (Life Technologies) according to the manufacturer’s protocol, and cDNA was used as a template for PCR. qRT–PCR was performed using the ABI Prism 7500 Fast Sequence Detection System (Life Technologies) in accordance with the manufacturer’s instructions. The TaqMan MGB used in the present study are shown in Supplementary Table 2. The thermocycling program was performed with an initial cycle at 95 °C for 20 s, followed by 45 cycles at 95 °C for 3 s and 60 °C for 30 s. Research grade human skin tissue sections were obtained from US Biomax Inc. (MD, USA) and human oral mucosal tissue was obtained from Science Care (Phoenix, AZ). The cells were fixed in 4% paraformaldehyde (PFA) or cold methanol, washed with Tris-buffered saline (TBS, TaKaRa Bio) three times for 10 min and incubated with TBS containing 5% donkey serum and 0.3% Triton X-100 for 1 h to block non-specific reactions. They were then incubated with the antibodies shown in Supplementary Table 3 at 4 °C overnight or at room temperature for 3 h. The cells were again washed twice with TBS for 10 min, and were incubated with a 1:200 dilution of Alexa Fluor 488-, 568-, 647-conjugated secondary antibodies (Life Technologies) for 1 h at room temperature. Counterstaining was performed with Hoechst 33342 (Molecular Probes) before fluorescence microscopy (Axio Observer.D1, Carl Zeiss). Fabricated human iCEC sheets were fixed with 10% formaldehyde neutral buffer solution (Nacalai Tesque, Kyoto, Japan). After washing with distilled water, the human iCEC sheets were embedded in paraffin from which 3-μm-thick sections were cut. These were stained with haematoxylin and eosin following deparaffinization and hydration. The sections were observed with a NanoZoomer-XR C12000 (Hamamatsu Photonics, Hamamatsu, Japan), BZ-9000 (KEYENCE, Osaka, Japan) and an Axio Observer.D1. Differentiated human iPS cells (more than 12 weeks of differentiation) were fixed with 10% formaldehyde neutral buffer solution, after which PAS staining was performed with a PAS staining kit (MERCK KGaA, Darmstadt Germany) according to the manufacturer’s protocol. The sections were observed with an Axio Observer.D1. Epithelial cells were seeded onto MMC-treated NIH-3T3 feeder layers at a density of 3,000–20,000 cells per well. These were cultivated in CMM for 7–14 days. The colonies were fixed with 10% formaldehyde neutral buffer solution and then stained with rhodamine B (Wako). Colony formation was then assessed using a dissecting microscope and the colony-forming efficiency (CFE) was calculated. For the holoclone analysis, a single human iCEC colony derived from the SEAM was cultivated on 3T3-J2 (provided by H. Green, Harvard Medical School, Boston, MA) in CMM for 7–11 days was picked up under a dissecting microscope and dissociated by TrypLE Select (Life Technologies). The dissociated human iCECs were again seeded on a MMC-treated 3T3-J2 feeder layer and cultivated in CMM for 10–13 days. The colonies were scored under a microscope and classified as holoclones, paraclones or meloclones based on previously reported methods27. Human CECs were harvested from corneoscleral rims (Northwest Lions Eye Bank, Seattle, WA) as reported previously28. Human CECs and human oral keratinocytes (OKs; ScienCell, Carlsbad, CA) along with SEAM-derived human iCECs were cultivated on LN511E8 coated cell culture inserts in CEM until confluent. They were then cultivated in CMM. Human dermal fibroblasts (DFs; ScienCell) were cultivated in DMEM/F12 (2:1) containing 10% FBS. Total RNA was obtained from human iPS cells, iCECs, CECs, OKs, DFs, and six-week differentiated iPS cells (that is, OSE) using the QIAzol reagent. A microarray analysis using Sure Print G3 human 8x60K slides (Agilent technologies, Palo Alto, CA) was performed at Takara Bio. The data were analysed using the GeneSpring GX software program (Agilent technologies). Microarray data used in this study are deposited in Gene Expression Omnibus under accession number GSE73971. The cultivated epithelial cell sheets were fixed in 2.5% glutaraldehyde (Nacalai Tesque) at 4 °C overnight. Subsequently, the sheets were washed in buffer, dehydrated with ethanol and tert-butyl alcohol (Wako), and critical point dried (JFD-320, JEOL, Tokyo, Japan). After sputter-coating with platinum in an auto fine coater (JFCL-1600, JEOL), the samples were observed by scanning electron microscopy (JSM-6510LA, JEOL) at 5 kV. FACS-isolated human iCECs were cultivated on MMC-treated NIH-3T3 feeder layers in CMM up to 70–80% confluence. The human iCECs were harvested using TrypLE Select following the removal of feeder cells by manual pipetting. The total cell numbers were counted, after which the cells were passaged at a 1:8 ratio onto newly prepared feeder layers. These were cultivated in CMM until sub-confluence was reached again. The G-band karyotype analysis for human iCECs was performed at Nihon Gene Research Laboratories (Sendai, Japan). All animal experimentation was performed in accordance with the ARVO Statement for the Use of Animals in Ophthalmic and Vision Research, and was approved by the animal ethics committees of Osaka University. To examine embryonic mouse eyes, pregnant females (C57/BL6, E9.5–18.5) were acquired from SLC Japan (Shizuoka, Japan). For the transplantation experiments, Female New Zealand white rabbits (2.5–3.0 kg (approximately 12–14 weeks)) were obtained from Kitayama Labes (Nagano, Japan). Harvested human iCEC sheets were grafted onto rabbit corneas, in which a total epithelial limbal stem-cell deficiency had been created following a corneal and limbal lamellar keratectomy (Extended Data Fig. 8c–j). After surgery, 0.3% ofloxacin ointment (Santen Pharmaceutical, Osaka, Japan), 0.1% betamethasone phosphate eye drops (Shionogi Pharmaceutical, Osaka, Japan) and 0.1% sodium hyaluronate eye drops (Santen Pharmaceutical) were applied three to four times per day. Triamcinolone acetonide (8 mg; Bristol Myers Squibb, Tokyo, Japan) was also administered by subconjunctival injection. Tacrolimus (0.05 mg kg−1 per day, Astellas Pharma, Tokyo, Japan) and Mizoribine (4.0 mg kg−1 per day Sawai Pharmaceutical, Osaka, Japan) were systemically administered using an osmotic pump (DURECT, Cupertino, CA). The corneal barrier function following surgery was assessed by 0.5% fluorescein eye drop instillation at day 7 and day 14 after surgery and the fluorescein negative area was calculated using the AxioVision software program (Carl Zeiss). Throughout the healing period, the cornea was observed with a digital slit-lamp camera (SL-7F, TOPCON, Tokyo, Japan) and 3D OCT1000 MARK II (TOPCON) or CASIA SS-1000 (TOMEY, Nagoya, Japan) machines. If an infection was found or if unexpected weight loss occurred, animals were excluded from the analysis. The rabbits were euthanized by the intravenous administration of sodium pentobarbitone 14 days after transplantation, after which the eyes were immediately enucleated for the histological analyses. No blinding or randomization was conducted to allocate animals to each group. The data are expressed as means ± standard deviation (s.d.). The statistical analyses were performed using the Mann–Whitney rank sum test or Steel’s test. Bonferroni’s correction was applied to the data in animal experiments. All of the statistical analyses were performed using the JMP software program (SAS institute Inc., Cary, NC). No statistical methods were used to predetermine sample size. Comprehensive technical details can be found in Protocols Exchange, http://dx.doi.org/10.1038/protex.2016.009.
News Article | March 31, 2016
The CFE-CGC Energy Union has said investment in the huge Hinkley Point C nuclear power plant development should be delayed by several years until some potential problems can be worked out. The £18bn project, if completed, could provide about 7% of UK’s electricity, so it’s obviously a massive project. Engineers at the French utility EDF have also called for delay, saying that the project is very complicated and unproven. “Right now, Hinkley is too risky for the company. We think it is better to wait and see. Wait for three years so we can see that everything works… or not,” said Francis Raillott from CFE-CGC. The project is so huge that reportedly up to 25,000 jobs could be created during the construction phase. This new reactor type has had some problems during construction, “The world’s first EPR at Olkiluoto in Finland is still not finished after eight years. Construction started on an EPR at Flamanville in France in 2007, but completion has been delayed until 2016. However, two EPRs at Taishan, China, should be finished within a year.” Recently it was reported that a British parliamentary committee had asked for information about plans and potential costs if the massive project should fail. The project was designed to use two EPR reactors situated in Somerset, England and have a capacity of 3,200 MWe. There are already two nuclear power stations in the area: Hinkley Point A and Hinkley Point B, but only the latter is still operational. In addition to the potential design issues, some have commented on the high cost, “We are frankly staggered that the UK Government thinks it is appropriate to take such a bet and under-write the economics of any power station that costs £5m per MW and takes 9 years to build,” said Peter Atherton from Liberium Partners. Of course, the main reason for building it is to add electricity generation capacity, and nuclear does fit the bill in terms of not using carbon-emitting fossil fuels. Building such a large, high-cost plant does also seem risky — especially if it proves in the end to have any problems when it goes live. Image Credit: Richard Baker, Creative Commons Attribution Share-alike license 2.0 Get CleanTechnica’s 1st (completely free) electric car report → “Electric Cars: What Early Adopters & First Followers Want.” Come attend CleanTechnica’s 1st “Cleantech Revolution Tour” event → in Berlin, Germany, April 9–10. Keep up to date with all the hottest cleantech news by subscribing to our (free) cleantech newsletter, or keep an eye on sector-specific news by getting our (also free) solar energy newsletter, electric vehicle newsletter, or wind energy newsletter.
Mexico just concluded its first Clean Energy Auction for energy, power and Clean Energy Certificates for purchase by CFE, Mexico’s only utility. The results are stunning -- 11 PV projects have been awarded contracts worth 4 million megawatt-hours (DC) per year. That translates to 1,860 megawatts of capacity (using an average capacity factor of 33.6 percent). Additionally, all 11 projects have won contracts for a combined 4 million Clean Energy Certificates (CELs). The winning projects are from seven developers: Mexico defines clean energy quite broadly, so the auction was open to competition from wind, hydro, cogeneration, combined-cycle gas, and geothermal, as well as PV. Out of a total 5.38 million megawatt-hours of energy that was awarded, PV won 74 percent and wind won the remaining 26 percent, with no contracts won by any of the other technologies. The scale of PV’s win is significant. According to data from GTM Research’s Latin America PV Playbook, Mexico has a cumulative 246 megawatts installed, with only 104 megawatts of that installed in 2015. Of that, only 50 percent are utility-scale projects. In early 2016, we forecasted a total of 382 megawatts of PV in Mexico for this year, with only 300 megawatts of that coming from utility-scale projects. All of this was expected from projects grandfathered in under the previous Self-Supply and Small Power Producer programs now discontinued under the new energy transition law. No further demand was forecast for the year. As for the auction scheduled for March 2016, consensus at Solar Summit Mexico, Greentech Media’s first international solar conference held in Mexico City in late January, was that solar would not win more than 200 megawatts. Based on what we saw in the market, however, our own estimates were more optimistic -- there was serious interest in the auction from well-established international companies, including some of the larger developers here in the U.S. -- and we therefore estimated solar to win as much as 500 megawatts in the auction. With project completion deadlines set for early 2018, that translated to 500 megawatts of solar demand forecasted for 2017. Solar’s win of 1,860 megawatts in the auction is a significant jump for the market. We now estimate total demand at 646 megawatts in 2016 (an additional 264 megawatts) and 1,513 megawatts in 2017 (an additional 836 megawatts) tied directly to the auction. That’s a 104 percent jump in the forecast across the two years combined. As a result, solar in Mexico will now grow by 521 percent in 2016 as opposed to the earlier 267 percent forecast and 134 percent in 2017 as opposed to the the earlier 77 percent forecast. Along with the jump in demand numbers, the average contract price of $50.7 per megawatt-hour is noteworthy as well. While not as low as the $40.5 per megawatt-hour that was first reported by news outlets based on a yet-to-be-confirmed list of winners, this average is nonetheless very aggressive -- the range is from $35.44 per megawatt-hour for a 427-megawatt project by Enel to $67.5 per megawatt-hour for a 29-megawatt project by Photoemeris Sustentable. By comparison, lowest PPA prices in other countries are much higher. How does all of this make sense? Well, clearly the solar industry globally has seen an opportunity in Mexico that has already been acknowledged by the likes of SolarCity last year. Low labor costs, excellent irradiation, a stable economy, and a strong PPA by a government-backed utility in the auction are some of the common reasons why local developers and experienced international players alike have flocked to Mexico for a piece of the solar pie. Mexico is a growing energy market with historically rising electricity prices. With the government’s goal of 35 percent of renewables by 2024 and 45 percent by 2036, the market for solar could be as large as 4 gigawatts to 6 gigawatts annually by 2030. Developers are certainly making a strategic play in Mexico with an eye on the market’s long-term growth. Internal rates of return (IRRs) on projects should be in the double digits for developers to justify investing in a developing market like Mexico. Access to international, low-cost financing due to U.S.-dollar-denominated contracts and very large project sizes (the average is 150 megawatts, with the largest being a 427-megawatt project by Enel) are certainly big factors in keeping costs down. Completion deadlines between January to March 2018 add pressure on developers to start construction soon. Developers then might have to go lower than double digits on their IRRs to install projects on time and avoid penalties that are set at a proportion of the loss to the offtaker from undelivered energy per day (more on that in the upcoming Latin America PV Playbook Q2 2016 report). With 3.4 gigawatts now planned between 2016 and 2018 (including some direct PPA and merchant sales projects), it remains to be seen if the market will be able to deliver on this pipeline. We are already expecting that at least 300 megawatts from this auction could get delayed and spill over into late 2018. While solar’s stunning win in this auction no doubt bodes well for PV in Mexico for the long run, we will be waiting to see how these projects get executed and whether all the awarded capacity will indeed be installed on time.
A dielectric material, when subject to an electric pulse, will absorb heat from or cool the surrounding. Credit: X. Qian and Q.M.Zhang/PSU Turn on an electric field, and a standard electrocaloric material will eject heat to its surroundings as its internal dipoles reorder themselves. Do the same thing, and a negative electrocaloric material will absorb heat, cooling the environment, thanks to the blend of ferroelectric polymers that make up each. While these materials have been investigated as a method of on-demand microclimate control for quite some time, there's a catch - the external field needs to remain active, which is energy-consuming and ends up heating the material. Recently, however, researchers at Pennsylvania State University have developed a unique blend of ferroelectric polymers which can hold absorbed heat even after the external field has been switched off - a system which could be adapted for a variety of small-scale systems. In a typical electrocaloric material, heating and cooling are only generated when the field is changing in response to a full electric pulse. Here, the amount of heating is slightly greater than the amount of cooling, with the difference depending on the material's efficiency. The researcher's anomalous electrocaloric material flips this, generating cooling when the field is turned on, but no subsequent heating when the field is turned off, other than the miniscule amount of heating generated in the dielectric material by the electric field. "The advantage of the electrocaloric material is its very high efficiency, compared with other solid state coolers, such as the thermoelectric cooler," said Xiaoshi Qian, a post-doctoral scholar and primary investigator on project. According to Qianm this can be attached to a chip or a biological system in need of on-demand cooling. Qian and his colleagues, including Qiming Zhang, also a professor at Penn State, describe their novel hybrid dielectric material this week in Applied Physics Letters. This allows the materials to either add or remove heat from a system through an internal reordering of dipoles - the separation of positive and negative charges. The researchers' electrocaloric material consists of a hybrid normal ferroelectric polyvinylidene fluoride-trifluoroethylene copolymer and a relaxor ferroelectric chlorofluoroethylene terpolymer. According to Qian, the bulkier third monomer CFE in the terpolymer introduces defects in its polymer chain, causing it to exhibit dipolar randomness rather than the ferroelectric ordering shown in the copolymer. When these form a finely-tuned blend, the resulting hybrid can be poled into one dipolar direction with an electric pulse, owing to the formation of strong macroscopic ferroelectric domains. Then, when subjected to a second, smaller pulse, the material becomes depoled, or randomly poled, and maintains this state. This allows their ferroelectric material to not only maintain a large cooling effect when a voltage is applied, but after it has been removed. Their experimental cycle consists of two electric pulses which operate in bipolar directions. The first pulse orders the hybrid's poles into a macroscopic polar-state, followed by a second de-poling pulse which transitions the material to a dipole random state. This yields a large cooling effect when the polymer blends display a large entropy increase due to the disordering. "We would like to improve the electrocaloric materials in the future so that the cooling generated upon an electric pulse in the EC material can be much larger," Qian said. "This study is the first step toward that direction." More information: "Anomalous negative electrocaloric effect in a relaxor/normal ferroelectric polymer blend with controlled nano- and meso-dipolar couplings," Xiaoshi Qian, Tiannan Yang, Tian Zhang, Long-Qing Chen and Q. M. Zhang, Applied Physics Letters April 5, 2016. DOI: 10.1063/1.4944776
Having established a presence in Turkey and Dubai, British solar developer Hive Energy continues its international expansion into Mexico, where the newly created wholesale energy market and upcoming electric-power auctions offer new opportunities for growth. The company is considering 300 megawatts' worth of projects in the country. But obstacles remain, said Bernardo Fernandez, Hive Energy’s director of Mexico operations. “The energy reform still needs to iron out a few wrinkles; they’ve been running a little fast,” he told GTM in an interview. “But the foundations are there, and as time goes on, we will see some minor modifications to the legislation to address minor issues.” Mexico’s energy reform puts an end to the monopoly of state utility CFE by opening up the market to outside bidders. CFE will participate in auctions both as supplier and offtaker, while remaining in control of the country’s transmission infrastructure. The first electric power auction is slated for March 31. Hive Energy has installed around 30 solar farms in the U.K. totaling 300 megawatts of capacity. In Mexico, the company is targeting CFE, private firms and public institutions as potential offtakers. “Our business model targets any institution that can provide a long-term PPA,” Fernandez said. “The CFE and energy ministry (Sener) are offering 15-year PPAs in this auction, while there are private companies willing to sign 20-year PPAs. The way the market evolves over the next 12 months is crucial, because companies are more than happy to sit it out for one year and see the reality of the new market and what the prices are compared with what CFE is offering.” He said Hive Energy would also likely sit it out and watch the market evolve before committing itself to a long-term PPA, while seeking to spread itself out. “We don’t know what the electricity market is going to be like.” “We need a healthy mix of offtakers in both the private and public sector, because if we just focus on the private sector, we might find ourselves with projects but no offtakers, and then have a company offer us less than the current CFE price, which is unbankable.” However, he said public-sector projects are harder to develop because, as a federal state, Mexico has so many layers of government. “Every layer is a hurdle, whether due to bureaucracy or personal relationships, and we need to navigate through that. Also, this country has a big problem with corruption, and while we don’t want to get involved in that, we will unfortunately be competing with companies that don’t care about that.” He cited Mexico’s national water commission (Conagua) as a potential client as it seeks to reduce water-pumping costs with sustainable energy use across its vast aqueduct network. Local governments seeking to reduce their municipal lighting costs are also potential customers. Harnessing its experience as a rooftop developer in the U.K., Hive is targeting companies looking at distributed generation projects between 5 megawatts and 10 megawatts. But first the company will watch to see how the market plays out. Energy prices dropped month-on-month in 2015 as a result of increased natural-gas use and a 40 percent spike in hydroelectric generation, according to the CFE. That makes solar less competitive. Industrial tariffs are now around 20 percent lower than in 2014, the CFE claims. “As the energy reform settles in and the first couple of auctions take place, electricity prices will show a tendency,” Fernandez said. “In 12 months’ time, that tendency will indicate whether trying to provide rural distributed electricity to small schools is a profitable enterprise or not. It’s something to keep an eye on, but we think there are way more opportunities out there in large-scale utility projects.” That uncertainty regarding the future of electricity prices is holding back PPAs. “It’s a long and difficult road, and it’s much more difficult to build relationships in Mexico than in Europe,” he said. “But, unlike in Europe, once the relationship is established, the benefits can be greater from a business point of view. Once you’re in that inner circle, it helps.” He highlighted the mechanisms that have been created to favor renewable energy development in Mexico, such as the clean energy law that establishes generation goals and the clean energy certificates (CECs), similar to carbon credits, that Sener will issue from 2018. However, “the rules of how they are going to operate are still not clear. There are a few gray areas that, in my interpretation, will eventually require new legislation,” he said. He also expressed concern as to how the electric power auction would work, given that Sener has yet to announce which projects will be put out to tender. “We anticipate that the first auction will be messy, and there are several factors that make it less interesting, regardless of what the big players say. Anybody that produces clean energy can participate, including enormous co-generation plants," said Fernandez. Natural gas plants will compete against renewable energy plants, which could impact the competitiveness of solar. He also expects a scramble for development that could drive prices down. “The solar industry in Mexico is so attractive. It has been attracting a huge amount of interest over the last three or four years, and there is an enormous array of developed projects out there which cannot find a PPA or an offtaker. I think they will be in the auction because they are desperate to flip their projects and willing to accept lower prices," he said. Mexico added 100 megawatts of solar in 2015, bringing the country's total capacity to 260 megawatts. It is expected to add a similar amount this year, according to Anes, the country's National Association of Solar Energy. Fernandez cited one last challenge: narcos. The region most ripe for solar development, the country’s northwest, is also a stronghold for drug traffickers. “It’s something that you try to put under the rug and hope it doesn’t affect you, but the more time you spend in the country, the more you realize it’s an important factor,” he said. “In the north of the country, there are companies that don’t pay their utility bill to the CFE -- they pay it to the narcos. And there will come a time when the narcos will educate themselves about solar, and projects could be affected. For the first couple of years, nothing will be done, until they realize the money that can be made." Make sure to tune in to our live stream of this week's Solar Summit Mexico, available only to GTM Squared members.