Mexico City is putting an 18 MW photovoltaic plant on the warehouse roofs of the Central de Abasto. When the first stage entered service on 13 June 2023, the Jefatura de Gobierno gave the installed capacity as 18 MW and the expected output as 25 GWh a year. The array sits on close to 20 hectares of roof over the fruit, vegetable and grocery halls, not on open land.
That roof figure is the one to carry into your own capital plan. Twenty hectares of committed roof for 18 MW works out at roughly 90 watts of installed capacity for every square meter of roof, on our arithmetic from the published capacity and area. A 10,000 square meter plant roof, on the same basis, supports something close to 0.9 MW.
The project is being read as proof that cities can go solar. On our read the transferable lesson is narrower. The Central de Abasto shows what a large aggregation of occupied, waterproofed industrial roofs costs to build and how long the build takes. It also shows why the roof owner ends up collecting rent and a modest bill saving rather than a 30% cut in its electricity spend. All three points apply directly to a manufacturing plant or a logistics park.
What was announced, and what it cost
The Mexico City government said on 15 February 2022 that construction would start that March, with 400 million pesos from SENER's Fondo para la Transición Energética y el Aprovechamiento Sustentable de la Energía, known as FOTEASE. The statement described two phases, rooftop systems on the bodegas followed by a central of up to 17 MW producing 25 GWh a year, with 36,000 photovoltaic modules in place by the end of 2022. It put avoided emissions at 12,404 tonnes of CO2 a year.
By 22 January 2023 the budget reported by Expansión had moved to 600 million pesos, 500 million of it from FOTEASE and 100 million from the city. The same report set out a three stage commissioning schedule of 1 MW in early February 2023, 8 MW in April and 9 MW in June. Forbes México reported on 8 April 2022 that works began on 31 March 2022, and that Fortius Electromecánica of Jalisco won the first construction contract at about 25.1 million pesos.
Take the 600 million pesos against 18 MW and the plant lands at roughly 33 pesos per watt of installed capacity. That is the figure to hold a rooftop quote against. It is high for bare modules and inverters because it is not buying only modules and inverters. It is buying structural work, waterproofing and staged access on roofs that stay in commercial use throughout.
The roof is the constraint, not the land
Surrounding land use is beside the point for a rooftop project. What matters is the condition of about 20 hectares of concrete roof over bodegas that trade every day of the year.
Two consequences follow, and both show up on any Mexican industrial roof of scale. The first is phasing. A 1 MW stage, then 8 MW, then 9 MW is not how you would build on greenfield. It is how you build when every roof section has an occupier underneath who cannot lose access. The second is labor supply. Mexico City's Secretaría de Desarrollo Económico ran solar installation and supervision training under the city's Ciudad Solar program, working with a certified provider. The courses ran against the CONOCER competency standards EC0586.01 for installing photovoltaic systems and EC1181 for supervising them. pv magazine México published the call on 31 January 2023. A project this size had to help build its own installer pool.
On the engagements Mexico Energy Partners has run, the roof survey is the item that most often changes a rooftop business case after the quote is signed. Membrane age, remaining waterproofing warranty, purlin spacing and permissible additional load decide whether ballasted mounting is available or whether the roof must be penetrated and resealed. That work belongs before the equipment order. For the wider background, see our note on the case for rooftop solar on industrial buildings.
Why the site owner collects rent, not a 30% bill cut
Expansión reported on 22 January 2023 that the completed plant would represent about 30% of the energy the Central de Abasto consumes in a year. That is energy, not cost, and the two are not interchangeable under a CFE demand tariff.
A large market or plant on medium tension buys under GDMTH, the Gran Demanda en Media Tensión Horaria schedule whose structure CRE set in Acuerdo A/058/2017 of 23 November 2017. That bill carries a capacity charge and a distribution charge billed on measured demand, alongside energy charges split across base, intermedia and punta hours. Photovoltaic output peaks near midday. The punta window in the central region falls in the evening. Displacing 30% of annual kWh therefore does not remove 30% of the invoice, because the demand components barely move.
The reported cash tells the same story. The Jefatura de Gobierno announced both figures on 13 June 2023, a saving to the Fideicomiso de la Central de Abasto of 3.5 million pesos a year and 127,000 pesos a month from the first stage. They are not two points on one line, since twelve months at 127,000 pesos is 1.5 million and the first stage is 1 MW of 18 MW. Forbes México reported in April 2022 that CFE would operate the plant and pay about 1.6 million pesos a year to rent the roofs. The same report noted that Mexico City had become the first state entity authorized to place surplus output into the Mercado Eléctrico Mayorista through CFE. The roof owner here is a landlord with a partial hedge, not a self supplier.
What changes when the roof and the load are both yours
An industrial reader cannot copy this structure, and does not need to. Article 17 of the Ley de la Industria Eléctrica, published in the DOF on 11 August 2014, exempts generation below 0.5 MW from holding a CRE generation permit. Anything above that threshold is a central eléctrica with a permit and a market route, which is why the Central de Abasto plant needed one. Below it, the system is generación distribuida.
The exemption covers the generation permit and nothing else. A rooftop system below 0.5 MW still needs an interconnection contract with CFE Distribución, municipal construction and land use approval, and structural and electrical sign off. CRE's distributed generation rules, issued as RES/142/2017 and published in the DOF on 7 March 2017, offer three schemes. Under medición neta, the scheme almost every Mexican site uses, exported energy is credited against later consumption rather than paid in cash. Credit still unused after twelve months is liquidated at the local marginal price of the node. Facturación neta pays the local marginal price for injections, and venta total sells everything at that price with nothing self consumed. We set out the mechanics in our note on how distributed generation is regulated in Mexico.
The consequence is a sizing rule. Export is worth the node price. Self consumption is worth the retail tariff you avoid, and the gap is large. Size the array to daytime on site load, not to available roof.
Three numbers to test your own site with
Roof density comes first. Roughly 90 watts per square meter of committed roof, drawn from the Central de Abasto figures, gives a first pass on capacity before anyone visits. Second, specific yield. The city's own 25 GWh against 18 MW implies about 1,390 kWh per installed kW each year in the Valle de México, close to a 16% capacity factor. A vendor projection for a comparable site that runs well above that needs an explanation you can follow.
Third, the share of your consumption that sits inside punta hours. Pull twelve months of CFE bills and separate the energy charges from the capacity and distribution charges. Solar moves the first group. It moves the second only if peak demand falls in daylight, or if storage is added to shift it. Mexico City's broader program, covered in our piece on Mexico City's wider renewable energy push, rests on the same arithmetic.
Find out what your own roof can carry
The Central de Abasto array works because the roofs were surveyed and prepared before a single module went up. Mexico Energy Partners runs that assessment on industrial and commercial roofs in Mexico. Send us the site address, the roof area and construction type, your CFE tariff class and RPU, and twelve months of bills. We will come back with usable roof area, an interconnection route, and the share of consumption a system could realistically displace. You can also start with a request for quote.
Sources
- Gobierno de la Ciudad de México, "Planta Solar en la Central de Abasto", 15 February 2022.
- Obras por Expansión, "Comienza la construcción de la planta solar en la Central de Abasto", 16 February 2022.
- Forbes México, "CDMX subirá la electricidad producida en la Central de Abasto al mercado mayorista", 8 April 2022.
- Expansión Política, "Planta Solar de la Central de Abasto en Iztapalapa estará lista a mitad de 2023", 22 January 2023.
- pv magazine México, "Capacitación en energía solar", 31 January 2023.
- pv magazine México, "En operación la 1era etapa del techo solar de la Central de Abasto de la CDMX", 13 June 2023.
- Ley de la Industria Eléctrica, Article 17, DOF 11 August 2014.
- CRE, RES/142/2017, disposiciones administrativas on generación distribuida, DOF 7 March 2017.
- CRE, Acuerdo A/058/2017, metodología y tarifas finales del suministro básico, 23 November 2017, as recorded in CRE's Memoria Documental Tarifas Finales del Suministro Básico of 31 October 2018.