[marwenchaabouni]

Adds the four equipment cost correlations verified during the review of #9. This is the subset that can merge on its own. The other nineteen rows stay in #9

Key	Equipment	Parameter	Form	Reference point	Exponent	cost_year
electrolyzer_pem_19009_2019	PEM electrolyzer, current (2019)	hydrogen production, kg/day	power-sizing	s0 = 1500, c0 = 2,132,440	f = 0.9255	2016
electrolyzer_pem_19009_2035	PEM electrolyzer, future (2035)	hydrogen production, kg/day	power-sizing	s0 = 1500, c0 = 1,337,870	f = 0.8621	2016
biomass_cfb_chp_irena_2012	CFB CHP	electrical capacity, MWe	power-sizing	s0 = 0.5, c0 = 7,395,000	f = 0.544	2010
electrolyzer_nrel_2008	Electrolyzer (PEM / alkaline)	hydrogen production, kg/h	offset power-law	a = 0, b = 224,490	n = 0.6156	2008

Sources:

• Saur (2008), https://doi.org/10.2172/944892
• IRENA (2012), https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2012/RE_Technologies_Cost_Analysis-BIOMASS.pdf
• Peterson, Vickers & DeSantis (2019), https://www.energy.gov/eere/fuelcells/hydrogen-production-cost-pem-electrolysis