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                                        Mainspring Energy
 
                                                 United States  -  Menlo Park, CA 
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                                                                                    1 Disclosed Funding Rounds $258,000,000
                                            0 Participating Investments
- 
                                                Founded date 
                                                
2010
 - 
                                                Operating Status 
                                                
Active
 - 
                                                Last Funding Type 
                                                
Seed
 - 
                                                Company Type 
                                                
For Profit
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                                            Mainspring designs and manufactures an advanced, flexible power generation solution — the Linear Generator —  that gives leading C&I companies, data centers, and utilities reliable, scalable,
                                        
                                        
                                        
                                                                                
                                        
                                                                                | Date | Round | Raised | Participating Investors | 
|---|---|---|---|
| April, 16 ,2025 | Series F | $258,000,000 | 
                                                
 M&G Investments
                                                                                
                                                                            
 Lightrock
                                                                                
 DCVC Bio
                                                                                
 Pictet Group
                                                                                
                                                                            
Green Gravity
 
                                            
enspired
 
                                            
Sweetch Energy
 
                                            
Helion
CNR (Compagnie Nationale du Rhône)
                                                                        
                                Helex |  $3,500,000  | (Nov 4, 2025)
                                                                        
                                xMEMS |  $21,000,000  | (Nov 4, 2025)
                                                                        
                                catalyx space |  $5,400,000  | (Nov 4, 2025)
                                                                        
                                Cephia AI |  $4,000,000  | (Nov 4, 2025)
                                                                        
                                Ornn |  $5,700,000  | (Nov 4, 2025)