鉆石城控股有限公司已在太陽能產業的第一筆投資，承諾投資KDC太陽能公司高達2億2500萬美元資金。KDC將在新澤西州開發商業太陽能項目。
在新澤西州，太陽能項目的再生，接收，以及出售實體都必須遵守國家可再生能源的相關要求。一般來說，可確保雙方合約與固定價格，具有可再生能源信貸長期合同，銀行為其提供項目融資的項目開發者獲收入來源更為穩定。
通過股權融資扶持太陽能項目，鉆石城控股所冒風險更大。沒有保證金，該公司資產增長步履維艱，因此該公司的輸電量也相對較少。
   一些私人控股公司也已步入發太陽能行業，包括能源投資合作伙伴，該公司曾出售大規模的公共事業太陽能面板給First Solar Inc., 和Denham Capital Management。

    Diamond Castle Holdings LLC has made its first investment in the solar industry, committing up to $225 million of equity in KDC Solar LLC, which will develop and own commercial solar projects in New Jersey.

    In New Jersey, solar projects can receive renewable energy credits that are then sold to entities that must buy them to comply with state renewable power mandates. Generally, project developers secure both contracts with buyers of the power, and fixed-price long-term contracts for the renewable energy credits to show banks that provide project financing that the projects will receive a steady stream of income.

   By financing projects entirely with equity, Diamond Castle is taking a greater risk than those that use leverage, and it also is going to develop fewer megawatts, as its capital won’t extend without leverage. In Ranger’s view, the firm won’t be leaving value on the table, either.

   Several private equity firms have taken stakes and exited from solar developers, including Energy Capital Partners, which sold utility-scale solar developer Nextlight Renewable Power LLC to panel maker First Solar Inc., and Denham Capital Management, which sold Italy-based SunRay Renewable Energy to SunPower, another panel maker, this year.