Quarterly report pursuant to Section 13 or 15(d)

7. Stock options and warrants (Details Narrative)

v2.4.1.9
7. Stock options and warrants (Details Narrative) (USD $)
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Dec. 31, 2014
Share based compensation $ 228,352us-gaap_ShareBasedCompensation $ 155,378us-gaap_ShareBasedCompensation  
Options      
Options outstanding 21,761,512us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
/ us-gaap_AwardTypeAxis
= us-gaap_StockOptionMember
  21,052,030us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
/ us-gaap_AwardTypeAxis
= us-gaap_StockOptionMember
Weighted average contractual life options outstanding 6 years    
Fair value of options at grant date 296,267us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1
/ us-gaap_AwardTypeAxis
= us-gaap_StockOptionMember
   
Aggregate intrinsic value of options outstanding 3,517,500us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue
/ us-gaap_AwardTypeAxis
= us-gaap_StockOptionMember
   
Share based compensation 207,425us-gaap_ShareBasedCompensation
/ us-gaap_AwardTypeAxis
= us-gaap_StockOptionMember
107,907us-gaap_ShareBasedCompensation
/ us-gaap_AwardTypeAxis
= us-gaap_StockOptionMember
 
Future unamortized compensation expense on unvested outstanding options 531,000us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions
/ us-gaap_AwardTypeAxis
= us-gaap_StockOptionMember
   
Warrants      
Options outstanding 5,392,087us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
/ us-gaap_AwardTypeAxis
= us-gaap_WarrantMember
   
Weighted average contractual life options outstanding 2 years 9 months 18 days    
Share based compensation 20,927us-gaap_ShareBasedCompensation
/ us-gaap_AwardTypeAxis
= us-gaap_WarrantMember
17,271us-gaap_ShareBasedCompensation
/ us-gaap_AwardTypeAxis
= us-gaap_WarrantMember
 
Aggregate intrinsic value of warrants outstanding 577,242us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueOutstanding
/ us-gaap_AwardTypeAxis
= us-gaap_WarrantMember
   
Future unamortized compensation expense on unvested warrants 25,138us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions
/ us-gaap_AwardTypeAxis
= us-gaap_WarrantMember
   
Warrants exercised 200,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercised
/ us-gaap_AwardTypeAxis
= us-gaap_WarrantMember
   
Proceeds from warrants exercised $ 50,000us-gaap_ProceedsFromWarrantExercises
/ us-gaap_AwardTypeAxis
= us-gaap_WarrantMember
   
Warrants expired 100,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExpirations
/ us-gaap_AwardTypeAxis
= us-gaap_WarrantMember
   
2004 Stock Option Plan      
Options outstanding 5,001,482us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
/ us-gaap_PlanNameAxis
= zero_StockPlanMember
  4,292,030us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
/ us-gaap_PlanNameAxis
= zero_StockPlanMember
Option shares available for grant 730,185us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant
/ us-gaap_PlanNameAxis
= zero_StockPlanMember
  1,439,637us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant
/ us-gaap_PlanNameAxis
= zero_StockPlanMember
Options granted 738,522us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod
/ us-gaap_PlanNameAxis
= zero_StockPlanMember
   
Options forfeited 29,070us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod
/ us-gaap_PlanNameAxis
= zero_StockPlanMember
   
Outside the Plan      
Options outstanding 16,760,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
/ us-gaap_PlanNameAxis
= zero_OutsideThePlanMember
  16,760,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
/ us-gaap_PlanNameAxis
= zero_OutsideThePlanMember
Options granted 0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod
/ us-gaap_PlanNameAxis
= zero_OutsideThePlanMember